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Frequently Asked Questions

Do you provide trained support for larger hot tub hire events?

Staffed and managed events are available exclusively by special arrangement with our live events partner

What are the pros and cons of an external wood-fired hot tub heater?

An external heater has long been a preferred option for many wood-fired hot tub manufacturers and is the go to heater for us here at Kirami, the worlds largest manufacturer. The heater sits to the side of the tub and is connected by pipes tot he tub body. Like all heater options there are some pros and cons of such a setup. 

1. Efficient and proven design, big heat outputs available to heat the water
2. Easy to operate, just like a log burner
3. Easy to clean, inside the furnace and the water jacket
4. More output options eg you can upgrade or change the size of heater at a future date
5. Ash and dirt from the logs don't fall in the water 
6. Heat abuse due to lack of water will not compromise the tub body, just repair or replace the heater only
7. Flexible layout, angle the heater using 90° pipes or extend it away from the tub

1. Larger footprint/space required than sub or internal
2. Heat can be lost/radiated from the heater body when the fire has gone out, Kirami tubs still only loose 10% of their temperature when left over night

What are the pros and cons of an internal wood-fired hot tub heater?

An internal heater is a popular option for a wood-fire hot tub. It is a heater which is built into the tub body of the tub and accessed form the outside of the tub. The flue then comes out of the side of the tub via a 90° bend. 

1. Fits within the tub body so minimises the tub foot print
2. Easy to access and load
3. Easy to operate
4. Easy to clean
5. Quick to heat
6. Looks smart and tidy

1. Hard to fix or replace if something goes wrong and all pipework is hidden in the body of the tub
2. Less upgrade options ie fixed size/output per tub
3. Heat abuse due to heating without water may compromise the integrity oft he whole tub rather than just the heater
4. Flue is close to the bathing area
5. Tub body is heavier to carry or lift into place as it includes the heater
6. Heater can take up bathing space

What are the pros and cons of a submersible or 'sub' wood-fired hot tub heater?

Submersible or sub heaters are usual stainless or aluminium boxes which are submerged in the bathing area, often protected from the bathers by a wooden gate or guard. The heater has two top openings, one for the logs to go in and ash to come out and one for the flue to attach.

1. Low cost of production
2. Fits within the tub so minimise the tub footprint

1. Ash and dirt from the logs can fall into the water
2. Hard to clean out as you have reach in with a special shovel/tool
3. Hard to load as you have to drop the logs in
4. Harder to operate/control as the logs are 'placed' on the fire
5. Risk of burns from reaching in
6. Takes up bathing space 

What is the difference between traditional and infrared sauna heating?

Infrared radiators do not heat up the sauna room efficiently on their own, they only radiate the heat to the bather. If an outdoor sauna only has IR in it the room can even feel cold. Hence we only have them as an additional option, not as a primary heat source. This way the traditional heater can heat up the room to a certain temperature, and IR can take care of the bather's heat.

Traditional sauna raises the body's core temperature slower because the heat is not directly radiated onto your skin. Some say that this would mean that IR is a more effective option for gaining health benefits than the regular sauna. On the other hand, regular sauna, with a high moisture rate, helps to stimulate your peripheral circulation better. As the hot moisture will quite literally get to your skin - everywhere.

A traditionally heated sauna raises the body's core temperature slower because the heat is not directly radiated onto your skin. Some say that this would mean that IR is a more effective option for gaining health benefits than the regular sauna. On the other hand a regular sauna, with a high moisture rate, helps to stimulate your peripheral circulation better. As the hot moisture will quite literally get to your skin, everywhere.

What fuels can I use to heat my wood-fired hot tub?

Dry logs which are under 20% moisture content are the perfect fuel for heating your wood-fired hot tub. If you don't have a current supplier look at the UK Ready to Burn scheme which is run by Woodsure to find a local reputable supplier.

You can also use charcoal and wood briquettes which are free from resin and glues, ie those which are compressed and bound by heat.

We do not recommend burning any of the following items

Wet wood

Painted or stained wood or pallets (except virgin timber one)

Wood pellet


Smokeless coal

Wood pellet

How do I clean my hot tub heater's water jacket?

When the tub is empty, point a high pressure hose through the top connection to the heater from the bathing area. If the tub is set up correctly where the heater is level and not sat below the body of the tub the water squirted into the water jacket will wash debris out of the bottom connection, underneath the tub and out of the water outlet on the opposite side to the heater. This can easily be done every time you change the water in the tub. 

A very useful feature of Kirami wood-fired hot tubs is this pipe which goes underneath the bathing area. Instead of washing debris back into the bathing area it allows it to be washed underneath and out down the drain.

Every 1 to 3 months depending on how much use the tub is getting we would recommend doing a full clean of the heater where you lift the flue off and remove the heater from the tub. The frequency of this will depend on whether you use any chlorine, bathing salts or other sanitisers and how often the tub is used, as well as how clean the bathers have been before bathing - often a challenge in an accommodation setting! 

Remove the heater from the tub by loosening one 13mm metal collar fastener on the top connection and one on the bottom. Slide the heater away from the tub and tilt it slightly to allow water and debris to drain when a high pressure hose is squirted into the top connection. This will remove any debris  which has accumulated in the base of the water jacket.

When refitting the heater it is important to ensure that the heater doesn’t sit too low against the tub, or debris will again accumulate in the bottom of it.

Use a 13mm socket or ratchet spanner to loosen and tighten the collar bolts. 

A popular inaccessible area cleaning product which is used across the wider electric spa and hot tub market is called Biofilm remover. This can be put into the bathing water with the heater attached to remove bacteria and dirt in any inaccessible pipework. 

Why is my hot tub heater smoking out of the door?

The usual cause of excessive smoke coming out of the furnace door is from the top baffle being in the wrong position.

The front of the top baffle should be completely in line with the opening of the furnace, not pushed back. There is a small bolt which sits in the middle of the baffle which stops it sliding back too far. This bolt needs replacing if it is missing. 

If you are in doubt or would like advice on your heater, send a photo to our business whatsapp number which is 01748 889303 or email to 

How does financing work?

We are delighted to have teamed up with Novuna, one of the UK’s leading financial services companies, to be able to offer finance packages to suit a range of consumer requirements including 0% finance for 12 months. Novuna, previously Hitachi Capital (UK) PLC.

We are delighted to be able to offer personal finance packages to suit a range of consumer requirements. Starting with an industry-leading rate of 0% APR, spanning over 12 months through to interest bearing credit at 9.9% for up to 60 months or Buy Now Pay Later with only a minimum 10% deposit to pay initially, nothing more for 12 months then the balance due at 12.9% APR for the remaining period. 

Please see the following useful information about the finance we can offer. 

Minimum age of 18 years old
UK resident of more than 12 months
Own personal bank account from which a Direct Debit can be taken
Permanent employment, working minimum 16hrs per week
Retired person
On disability allowance
Registered carer
Unemployed & ‘house person’ (with the consent of co-habiting working partner)
Payments will begin one month after the goods have been delivered.

Customers can change their payment date once they have received their welcome documents.

Yes, customers can make additional payments at any time free of charge.

Yes, please call our Customer Service team on 0344 375 5500 to discuss this in further detail.

The quickest and easiest way for customers to view their balance is by managing their accounts online. Customers can create an account or access a pre-existing account at

To apply for finance, you must be over the age of 18, work at least 16 hours a week, or be retired with an income. You must also be a resident of the United Kingdom and have lived in the UK for the last 12 months or more.

Unfortunately, we are unable to offer finance to residents of Eire. Homemakers aren’t excluded from applying under their own names; however, the employment details of your spouse/partner will be required in order to process your application.

No. There are no arrangement fees or hidden extras.

Applying for finance couldn’t be easier or more convenient. When you buy from us you have the choice of using finance and our staff will talk you through what is needed to process an application.

The whole process only takes a few minutes and is simple and secure. Once your finance application is approved, you will then be advised of how to sign the finance agreement and you will also receive an email confirming these details.

Please read the agreement carefully checking that all the details are correct, then electronically sign the agreement or print it.

Following receipt of your finance agreement and a few additional checks, your purchase can proceed.

All finance decisions will be made within seconds. Once you are approved, we will contact you (during working hours) to finalise your purchase. If your application is referred Novuna’s Underwriting Team will review your application and may request some further information from you before making their decision.

Within minutes of your application being approved, you will be presented with the option to e-sign your agreement.
If you choose to e-sign your agreement, a PDF of your agreement will be displayed on the screen. You should read the agreement carefully before clicking all the relevant sections agreeing to its terms. A copy of your credit agreement will be emailed to you once the e-signature has been completed.
Once you have agreed to the terms of the finance agreement the retailer will be notified and you need do nothing more.
Note that products will not be allocated to your order until your completed and signed agreement is returned and received by Novuna Personal Finance. Shipment of your goods will follow soon after your agreement has been returned and received.

Credit scoring is the process used by financial services companies to evaluate the credit risk of new applicants. This technique will be applied to your application for online finance. Credit scoring works by awarding points for each answer given on the application form such as age, income, and occupation, together with information obtained from credit reference agencies.

This information allows consistent decisions to be provided, ensuring all applicants are treated fairly. Credit scoring does not discriminate on the grounds of sex, race, religion, or disability.

In addition to credit scoring, Novuna also takes into account confirmation of your identity, validation of certain application details, existing commitments, and information held at the credit reference agencies. Though Novuna is unable to provide you with a main reason for declining your application, it is usually based on one, or a combination of the following:

Your credit score (please note that every finance company will score you differently)
Adverse credit reference agency information
You are considered to be overcommitted
You are aged under 18
Your existing account performance with other lenders

Some of the information is public information, for example, electoral roll, County Court Judgments, and bankruptcies. Other lenders may also file information about accounts you hold with them for instance this could include your payment history and outstanding balance on these accounts. Any requests for credit, where a credit reference search has been undertaken, will also be filed, although the result of the request is not recorded.

Send a request to the relevant credit reference agency, together with details of all addresses at which you have lived over the last 6 years:

Experian Limited, Customer Support Centre, PO Box 9000, Nottingham, NG80 7WF
Equifax Ltd., Customer Service Centre, PO Box 10036, Leicester, LE3 4FS
TransUnion International UK Limited, Consumer Services, PO Box 491, Leeds, LS3 1WZ
The above-listed agencies will provide details of information relating to these addresses. If you believe that the information is incorrect, you can ask the agency to correct it.

Yes. We acknowledge that circumstances change and just because a previous application has been refused, it does not mean that a further request will automatically be turned down. We do suggest, however, that you leave at least 6 months between applications.

The ‘rate of interest’ is the cost you will pay each year to borrow the money, expressed as a percentage rate. It does not reflect fees or any other charges. The ‘APR’ is a broader measure of the cost of borrowing than the interest rate. The APR reflects the interest rate and other charges that you pay to get the loan. The FCA description of any APR is “APR stands for the Annual Percentage Rate of charge. You can use it to compare different credit and loan offers. The APR takes into account not just the interest on the loan but also other charges you have to pay, for example, any arrangement fee. All lenders have to tell you what their APR is before you sign an agreement. It will vary from lender to lender

Why should I buy a Kirami hot tub?

Kirami are Europe's leading manufacturer of wood-fired hot tubs with 10,000 tubs manufactured each year. Based in Finland and distributed throughout Europe through a network of local resellers, our most popular tubs combine the traditional wooden barrel exterior aesthetics with easy care LDPE plastic interiors. Marine grade, laser welded aluminium heaters are designed to be used with all hot tub chemicals such as chlorine and bromine as well as salt water. All tub fittings are designed for performance and durability ensuring your tub functions well for many years.

By purchasing a Kirami tub, you are assured of a high quality product with ongoing support from the Kirami UK team, backed up by the team in Finland.

Unlike a number of other UK based retailers, we are delighted to show you our factory and who makes our products. This means we can provide you with technical support, spare parts and the reassurance that you are buying a know brand, safe product. Kirami is very well known in Finland and becoming increasingly recognised and popular here in the UK. 

Kirami is the only wood-fired hot tub manufacturer to participate in establishing the European standard for safety in hot tubs. Please see EU Safety Standard

What kind of maintenance measures does the FinVision Sauna need?

The outer and inner surfaces are treated again as needed. We recommend using environmentally friendly cleaning agents such as Kirami’s Biowash for washing the sauna. Landscape Window cleaning with window cleaning tools and agents. You can follow standard heater maintenance instructions and and you will find more detailed instructions in the FinVision - sauna user manual.

How to light a fire in a wood-burning sauna heater?

Only natural kindling and dry hardwood or softwood should be used for lighting a fire in a wood-burning sauna heater. The moisture content of the wood should be less than 20%. Good firewood consists of split wood with a diameter of around 5 cm, length of approx. 33 cm and weight approx. 0.5 kg. Stack the wood loosely into the firebox and light the fire from the top. A calm flame is a sign of suitable draft. You can adjust the amount of draft with the ash drawer. If the sauna heater makes a loud humming noise while heating, you should close the ash drawer more. When the flame is more even, the stones heat better and the flue does not get overheated. Low pressure may make lighting a fire in the firebox difficult; in that case, the sauna door can be held open for a moment and the ash drawer kept a bit further ajar until the firebox is properly lit.

Liquid fuel, cardboard or milk cartons must not be used for lighting fires. For lighting a fire, we recommend birch bark or flamers made from natural wood shavings and fully refined paraffin wax.  

Does the Sauna package include a heater?

All sauna packages include the Harvia electric or wood-fired heater, You can choose which you would prefer at the time of purchase. The sauna can also be ordered without a heater.

If specifying an electric heater it is important to determine how large an electrical connection you have available. 

These can range form a 3.4kW single phase connection to a 10.8kW three phase.

How to get the FinVision sauna in to place?

At Kirami UK we include lifting of the sauna into place as part of the cost of the sauna.

If you are able to lift the sauna yourself please let us know at the time of placing your order. 

We usually use a lorry with a hiab-crane which lifts the sauna straight into place from the lorry. In some cases, a long pallet truck or pump truck is also usaful to position the sauna.

The best options for delivery will be discussed when location of the Sauna is specified.

When transporting the sauna, the lifting slings, forklift tines or long pallet trucks must be placed under the pallet so that the pallet supports the elements as well as possible throughout the lift and the sauna remains straight and the lifting capacity constant. See example images on how to lift the sauna into place by using lifting slings or the tines of a forklift.

On what surface should the sauna be installed?

Placing the sauna on an even surface that can bear the weight of the sauna is important. The surface can be evened out with stone chippings, or if you want to have a more solid foundation, you can cast one from concrete. If you want to insulate the sauna foundation, we recommend placing at least 5–10 cm of ground frost insulation under the gravel, which effectively cuts off the thermal bridge to the cold ground underneath. Under the sauna, we recommend placing 9 concrete slabs on top of the hard surface to lift it higher (see the image of the foundation) and putting roofing felt (bitumen roofing) on top of the slabs throughout the width of the sauna. When the base of the sauna is clearly up in the air, it has ventilation and dries well.


Make sure that the ground on which the sauna is placed is stable. If necessary, the base of the sauna can be evened out with stone chippings or a concrete casting can be made under the modules. If you want to insulate the base, we recommend placing at least 5–10 cm of ground frost insulation under the gravel, which effectively cuts off the thermal bridge to the cold ground underneath. Never place the sauna directly on the ground. Pay attention to potential maintenance activities when choosing where to install the sauna. The warranty does not cover any indirect costs, such as the demolition or construction of terraces. Before building a foundation, it is also good to prepare for the drainage of water from the sauna to its final location (the sauna already has its own drainage installed).

Screw piles

There are various sizes, lengths and types of screw piles on the market. The selection is wide, because the choice of screw pile is also influenced by other things than the size and load capacity of the screw pile. The appropriate model is selected according to the type of soil and the depth of the frost line. You can install screw piles yourself, but ask a professional for advice on choosing a suitable model. 81

Concrete slabs

Under the sauna, we recommend placing concrete slabs on top of the hard surface to lift it higher and putting roofing felt (bitumen roofing) on top of the slabs throughout the width of the slab. When the base of the sauna is clearly up in the air, it has ventilation and dries well. It is also important to ensure that the sauna is not surrounded by tall grass, because it prevents the wood from breathing and contributes to rotting. The lower parts of the sauuna must always have enough ventilation. Below more detailed measurements of the concrete slabs.

In what kind of package is the FinVision sauna delivered?

The sauna is delivered already assembled except for the sauna heater, flue and door handle, which are be installed by us.

During transport, the sauna’s own base acts as the pallet, which means that the sauna can be placed directly on top of the foundation prepared by the customer. For transport, protective plywood sheets (attached with screws) have been placed around the FinVision sauna in addition to protective film. We only remove the covers after the sauna has been placed in its final location to ensure that the glass in the sauna remains intact.

How close to another building or neighbour can a sauna be placed?

We always advise that you check the fire safety regulations of your residential area from the local council or building authority as it may vary for each area.

The distance required to be left between a neighbouring boundary and your outbuilding is 2 meters with a building of no more than 2.5 meters in height.

In the UK, outbuildings such as Saunas, sheds and summer houses must be single storey. with a maximum eave height of 2.5 meters and a maximum overall height of 4 meters, with a dual pitched roof or 3 meters in any other case.

If the sauna is located close to buildings or integrated into the terrace, you must ensure that the chimney is sufficiently removed from all flammable structures. You should remember to check the distance both in the vertical and horizontal direction to ensure there is no danger of ignition. Follow the instructions provided with the sauna heater.

Does the sauna require building permit?

Building and layout specifications may vary by location, so you should refer to local guidelines. A structure equipped with a fireplace almost invariably requires approval from the authority.

What size is the FinVision Sauna?

The surface area of the sauna is 1.6m x 2.3m for the small sauna, 2.3m x 2.3m for the medium sauna and 2.3 x 4.6m for the large sauna, and the building height including the eaves is 2.55 or 2.5m (please advise your requirement at the time of placing your order). The sauna has been designed for 1 to 3, 4 to 6 or 6 to 8 people.


What material is the FinVision -sauna made of?

Kirami’s FinVision sauna shows the high-class finish of a master craftsman. The sauna is already surface-treated; it is made out of plain sawn softwood and spruce plywood. The product is intended for outdoor use only.

Is there anything particular I should bear in mind when dosing a filter less tub?

Always read instructions of your Biocool and dose accordingly ensure  you stir thoroughly to ensure that the disinfectant mixes well with the water. Dose after every bathing session and then wait 12 hours before bathing again to allow time for the product to dissolute.

How often do I need to change the water in a hot tub without a filter?

Water in hot tubs without a filtering system should be changed more often, as particles that accumulate in the water during bathing provide nutrition for microorganisms. Even if the water is disinfected, it will become turbid, indicating that there is growth in the water. Replace the water at least every three days, depending on how often you bathe.

Why doesn't my filter get clean?

There are a number of possible reasons; however, the most common cause is that the filter is old and requires replacement. It may also be heavily soiled and in need of cleaning twice in succession.

Do the following: Rinse off all visible dirt using a hose. Once rinsed, use BioCool Pool Filter Clean to dissolve fat and disinfect the filter. When the filter has been cleaned according to the manufacturer’s instructions, it is important to rinse off the dirt and fat released by the filter, including in folds in the filter. Use a hose to clean the filter, preferably with a nozzle. Allow the filter to dry for 24 hours before using again. The efficiency of the filter will decline over time and it can only be reused a limited number of times. Make sure you have spare filters at home so that you can easily replace them.  

How often should I replace the filter?

The frequency with which you need to replace your filter depends on the chosen supplier. Read the packaging to find out what applies to your particular filter. The working lives of all filters are extended by continuously cleaning and allowing the filter to dry for 24 hours after cleaning before use.

How often should I clean my filter?

You should regularly clean your filter using BioCool Pool Filter Clean, 1-4 times per month. During the high season you may need to clean your filter every week, while during the low season once a month should suffice. Water quality, circulation and bubble function are dependent on a clean. efficient filter.

The filter collects particles from the water. If the filter is heavily soiled, you may need to repeat clean and increase the frequency of cleaning.

If you are experiencing problems with foam, there are several things that you can do:

  • Turn off the bubble system (if you are using one).
  • Remove as much foam as possible from the hot tub.
  • Wipe away any brown line that has formed around the edge of the tub.
  • Make sure that the filter is clean and the circulation is active.
  • Let the water treatment system and the disinfectant do their job for a day or two. This usually causes the foam to disappear.
  • If you are still experiencing a problem, add a defoamer.

Other causes of foam formation could include ordinary surfactants that exist in many of our household products such as detergent, soap, shampoo and skin cream. If there are residues of surfactants on our swimwear, in our hair or on our skin, we take them with us when we get into the hot tub. When the surfactants end up in the warm water in the tub, they dissolve and may form foam in the tub.

Therefore, not only is it important to shower and wash away ordinary dirt before you get into your hot tub, it is also important to wash away any residues of soap or skin cream, and to ensure that your swimwear has been thoroughly rinsed.

Why has foam formed in the water in my hot tub?

When you fill the tub with new water and add Disinfect my pool, foam can sometimes form when you start the bubble system. This foam is formed by particles that already exist in your water and bind to the disinfectant. All water can contain particles, even water that looks nice and clear. The foam may have a slight brown colour, which is due to particles and dirt in the tub being collected by the foam.

Why has a brown line formed around the edge of the tub?

When you use the disinfectant Disinfect my pool in your hot tub, the active substance interacts with microorganisms and other particles in your water. The product binds to dirt in the water and a process of precipitation may occur, which can become visible in the form of a brown line around the edge of the tub.

If a brown line forms around the edge of your tub, wipe it away and make sure that the filter is clean and the circulation is active. Then let the water treatment system and the disinfectant do their job, and the water will clear up!

Should I turn on the bubbles when dosing BioCool Disinfect, as this is necessary when adding chlorine?

It is sufficient to have the circulation switched on in the tub for the product to effectively disinfect the water.

How often do I need to change the water in a hot tub or spa equipped with a filter?

The water change frequency will vary depending on the usage of the tub. Tubs which are more regularly used may require the water changing once a month, where  less frequent use may mean the tub will only require a water change up to once every three month.

When using BioCool products ensure you dose according to the manufacturer’s instructions and to replace the filter at regular intervals in order to ensure that pool water maintains an even quality.

Can hot tub water be drained directly onto the ground?

BioCool products are biodegradable. This means that in most cases hot tub water can be drained directly onto the ground; however, each municipality has its own regulations for emptying the tub water. We therefore recommend that you familiarise yourself with local regulations before emptying your tub.

What happens if I accidently put too much BioCool in my tub?

A slight overdose of BioCool products presents no danger. We do however recommend that you avoid bathing for 12 hours after any overdose, apply the same principle as you would when Chemically treating your hot tub with a standard dose and treat water 12 hours before tub use. If you happen to overdose severely, please contact BioCool for further information:

Why does BioCool Pool Disinfection eliminate the need to check the pH of my pool?

Chlorine is sensitive to the pH level of water and requires a constant pH level between 7.2-7.6 in order to function. When using conventional chlorine, a low pH level (acidic) may cause eye and skin irritation, as well as corrosion to pool accessories and equipment. If the pH value is too high, the chlorine will be less effective and algal growth will increase rapidly in the pool water.

BioCool Pool Disinfection,  BioCool’s products differ significantly in that they disinfect the water regardless of pH level, making monitoring unnecessary. 

What is the difference between standard chlorine and BioCool Pool Disinfection?

The most important differences between chlorine and BioCool pool products are:

  • BioCool does not release any active chlorine and therefore does not generate any chloramines that can present a health hazard and lead to allergies.
  • BioCool is odourless.
  • BioCool is easily biodegraded in nature.
  • BioCool is easy to use as it can be dosed directly from the bottle without spillage. You avoid the need to measure free and bound chlorine, pH and alkalinity.
  • No supplementary products are required.
  • BioCool has been proven to be effective in both laboratory tests and tests on extensively used pools.
How Biocool Disinfect my pool works?

The active substance in Disinfect my pool – Didecyldimethylammonium chloride (DDAC) – has a long carbon chain, and this "tail" penetrates the cell membrane of bacteria, which causes the bacterial membrane to start to leak, and the cell dies. The same principle applies to viruses where DDAC also has an effect.

Can I rent a hot tub from Kirami UK?

Yes here at Kirami UK we do have a rental service available for hot tubs.

Our most popular hire hot tubs are our M size, with seating for up to 6 people per tub. We are able to deliver to most locations within our free delivery area. If delivery is a remote location or somewhere with restricted access, or you would like further information on our rental service, please give us a call or send your query to our WhatsApp Business number which is 01748 889303.

What should I do if a new hot tub is leaking?

That depends on where the leak is located. Check the heater connection hoses to make sure that there are no wrinkles in the rubber hose inside the clamp and that there is enough overlap with the inner pipe, and tighten the clamps.

In the outlets and other parts where threads need to be sealed with thread seal tape, make sure that there is enough tape to form a tight seal and that the threads are not tightened all the way. 15–20 even layers of tape on the thread is usually a suitable amount.

If you find you are still have issues, feel free to give us a call on 01748 889303, you can even Whats App us a video on the same number of your problem.

What should I do if the outlet valve is frozen?

You should try to thaw the frozen valve by pouring warm water on it. Slowly, the valve will regain its function. Do not attempt to open a frozen valve by force without thawing it first.

Can I change the location of the outlet valve?

The location of the outlet valve can be changed with a middle outlet set installed between the heater and the tub. The set is sold separately. With this accessory, the heater is installed further away from the tub, and the branch installed into the extension allows you to empty the tub from the heater side.

What size is the hose connection in the tub’s outlet valve?

A hose with an internal diameter of 38 millimetres fits the outlet valve of the tub. A hose in this size is available in our accessory selection in a coil of 10 metres.

Are there handrails available for the steps?

There are no handrails for our small steps, as the steps are so low and lightweight that a handrail would not be sturdy and safe. However, we now offer a higher and heavier Family step, which features a handrail.

Can I leave the cover on the tub when emptying the tub?

It is always advisable to remove the Hot tub cover or leave an opening when emptying the tub. If the cover is left closed you may find it will cause a vacuum making it difficult for you to remove the cover or result in the tub not emptying fully.

Can the cover be locked so that children won’t be able to open it?

A safety lock is available as an accessory for our covers. The safety lock is a belt that is installed over the cover and locked on the other side of the tub with a key. This prevents children from opening the cover on their own. From early 2019 onwards, the lockable belts will be included in our insulator covers as a standard accessory.

Will the cover stay in its place in windy weather?

Here at Kirami UK we include the necessary parts for securing you hot tub cover which will help keep your cover secure when we have windy weather.

The plastic cover includes rubber fastening bands, while the insulator cover includes fixed belts.

To attach the bands or belts to your tub you will need to attach the counterparts for the belts to the panelling on your hot tub.

What are the advantages of an insulator cover?

The purpose of an insulator cover is to preserve heat better. The benefits of the insulator cover are

This allows the tub to heat more quickly.

This helps reduce the temperature drop of the tub over night compared to the ABS cover.

Its easy manoeuvrability, as the cover folds in the middle. this feature also makes it easier when monitoring your water temperature for use as it saves removing the entire cover.

It is easier to store and takes up less space than the ABS cover due to the ability to fold.

Will the cover withstand different types of loads?

Our covers are designed to withstand the weight of snow very well.

The plastic cover is dome-shaped, which makes it easier for snow to flow away.

The insulator cover is reinforced with metal bracing, which helps improves its durability in challenging winter conditions.

Please be advised covers are not designed for people to sit or stand on. This will result in breakage.

Why are there no wooden covers available?

The longevity of a Wooden cover is a lot shorter than that of the Plastic and Insulated as it will soften, bend and swell with weather changes, which will make it heavier in weight but also affect its functionality and it will become less efficient..

Covers which are made of plastic and artificial leather are lighter, easier to manoeuvre, very durable and more suitable to changes in weather, plus easier to keep clean 

Why should I use a tub cover?

Th Cover for the tub is important for a number of reasons.

The cover acts an an insulator, helping your water come to temperature more quickly, without a cover the heat would disperse into the atmosphere this means you would require a lot more fuel for your burner and the tub would take considerably longer to heat.

The cover will help the tub hold the heat longer which will enable you to use the tub again the following day without a much shorter heating time required.

The cover will help prevent debris from blowing or falling into your bathing water when not in use.

The cover provides protection for the interior of the tub from the UV light.

The cover will also provide some peace of mind that children and animals do not have direct access to open water.

For M-sized tubs, you can choose a plastic cover or an insulator cover. You can only use an insulator cover on L and XL tubs.

How often should I replace the filter?

The cartridge has to be changed on a need to need basis, but at least once every season.

The running age of the cartridges changes accordingly to the usage of the tub and quantity of dirt in the water.

It makes sense to purchase a replacement cartridge at the same time as the actual filter. This will allow you the flexibility to alternate between the clean and dirty cartridges allowing adequate time for the filters to dry before re-use. This will help the cartridges last a bit longer and you can reuse them a few times.


Is it possible to keep water in the tub at a low heat during winter?

Here at Kirami UK we sell the Poolican, the link below will provide you with some information on a product we sell which will allow you to manage the temperature of your tub.

Why the stove does not have an air grid?

Cult and Macu stoves do not have an air grid as a standard.

At the beginning of 2018, a place for a grid has been added on the hatch. There is now a possibility to buy and install the grid for those stoves as an accessory. The air grid helps manage air circulation within the fire. To get the maximum power from your fire the grid must be fully open. When you wish to slow down the heat from the fire, you can narrow the opening of the grid.

What is a magnesium anode rod and what are the advantages of it?

Kirami’s magnesium anode rod.

A sacrificial anode rod that protects your heater from corrosion. The magnesium anode rod protects your heater from the corrosion that chlorine and seawater can cause. The rod should be checked twice annually and replaced every 6-18 months depending on use.


Can I install a pump between the hot tub and the heater?

This is prohibited, as the heaters are only designed for the natural water flow, and using a pump would cause the pressure inside the heater to increase. Starting and stopping the pump creates pressure shocks inside the heater that could break the heater.

How can I reduce the amount of sparks?

If sparks are causing you trouble, we recommend using our spark shield, this will help minimise the amount of sparks released into the environment and reduce the risk of igniting brash in the dry season. A conventional chimney cap will also help by preventing the chimney from rain.

Sparks can be caused due to the quality of the logs you are burning, If you find you are having problems with sparks, it could be for various reason such as moisture in the logs or the type of log you are burning.

Birch is a good wood to burn in your log burner, the amount of sparks exiting the chimney is very minimal.

Never leave a fire unsupervised.

How can I reduce the amount of smoke?

To avoid a smoky burn, use suitably small, dry and clean firewood with a moisture content of less than 20% or a good quality charcoal, do not use coal.

The following can cause your burner to smoke so should be avoided?

Logs with a high moisture content

Logs which have been treated with a chemicals.

General rubbish 

The heater has lost some of its efficiency and the heating takes longer than usual. What should I do?

If your heater is not heating as efficiently as it should be, it could be that you have a build up of sediment in the bottom of the water jacket part of the heater, or a build up of soot in the flue. 

It is good practice during water changes to rinse the heater's water jacket out using a powerful hose squirted into the top water outlet then every 1 to 3 months depending on the amount of use the tub is getting we recommend doing a full clean on the heater where you remove it from the tub. The frequency of this type of clean will depend on whether you use any chlorine or bathing salts etc, water hardness and how often the tub is used.

Removing the heater from tub to clean the water jacket is particularly important in a business setting where those using the tub might not be as clean as they should be. 

The process to clean the heater water jacket is as follows.

  1. Lift the flue off the top of heater, either in 1 or 2 pieces. Lie it down out of the way on a soft surface eg lawn or blanket
  2. Using a 13mm socket or ratchet spanner, loosen 1 top metal collar and 1 bottom metal collar
  3. Slide the heater away from the tub and tilt slightly so water can drain out of the bottom outlet
  4. Squirt water into the top outlet and allow sediment to be washed out. Repeat until water flows out clear and clean, often tipping the heater form side to side can help 
  5. Refit heater to tub, tighten collars and refit flue as it was

It is important to ensure that the heater doesn’t sit too low against the tub or debris will accumulate in the bottom of the heater rather than washing out via the pipe which runs under the tub. 

There is humidity inside the heater. Is the heater broken?

The temperature difference between cold water and warm, humid air causes condensation inside the ash compartment, so there are probably no leaks in the heater even if there is some humidity inside the fire chamber. Considerable condensation may occur when you light a fire, but if the water level in the tub does not change, there are no leaks.

How often should I empty the ashes?

The ashes must be emptied after every heating to prevent the grates from burning out prematurely and to ensure a good draught while heating.

Does the heater require soot removal?

The internal walls and pipes of the heater must be cleaned of soot when necessary. If you use a chimney cap with a spark catcher, it should also be cleaned every now and then to ensure a good draught.

Does the heater become hot?

The external surface of the heater will only become as hot as the bathwater. However, please note that the chimney and the heater door become hotter than the bathwater, as they are not in direct contact with the water.

Is a heater that is placed inside the tub more efficient than an external heater?

Almost all external heaters are more efficient than internal models. An external heater is considerably more user-friendly than an internal model, and it also saves bathing space. 

What are the required fire safety distances for the heater and the chimney?

The fire chamber of the heater is surrounded by a water jacket. This means that the temperature of the heater will not exceed the temperature of the water inside the heater. However, there needs to be a non-flammable protector in front of the fire chamber in case sparks or embers drop out of the chamber. Our selection of accessories includes a fireproof plate to protect the front of the fire chamber. As for chimneys, please refer to the fire safety distances presented in our instructions.

How does the hot tub filter work?

Kirami offers two filter options: a light filter and a sand filter.

The operating principle of the light filter is that water is first sucked through a coarse filter floating on the surface, from where it is transferred into a submerged fibre filter cartridge. A pump on the bottom of the device pumps the filtered water back into the tub.

The operating principle of the sand filter is that water is sucked out of the tub with a pump and transferred with pressure through the filtering material inside the filter tank, cleaning the water. For filtering material, you can use conventional filter sand or Kirami filter fibre.

Filters mix the water in the tub when used. Do not use a filter while bathing. Filters only remove mechanical dirt, while bacteria can be controlled with chemicals.

Why is plastic a good material choice for the hot tub?

Plastic is a good choice for the lining of a hot tub as it is durable, weather resistant, easy to clean and does not require much maintenance. You can clean it with a cloth and soapy water or even a pressure washer. It is environmentally friendly and recyclable.  

How do I know how much chlorine I should use in my Hot Tub bathing water?

Whenever using chemicals in your hot tub always read the directions printed on the product labels you are using, this will give you a guide to quantity of product you will need in relation to the water in your hot tub. 

Why am I unable to remove the rubber plug from the outlet valve?

From time to time the rubber plug may become stuck in the outlet valve. This can happen  if the plug has been tightened for a long time. If the plug does become stuck, we would recommend loosening the threads and giving the plug some time to regain its shape and loosen up before the removal.

You can prevent the plug from getting stuck with regular cleaning and keeping it loose/untightened when the tub is not being used. 

My wooden hot tub is leaking. What should I do?

Hot tubs that are made of Thermowood, will sometimes leak when used for the first time or if left unused for an extended period of time. This is perfectly normal, and the leaking will subside over time.

Hot tubs which are made of untreated spruce are known to shrink when not in use so will require time to swell once filled for the spruce to become water tight again. 

When a hot tub is used on a regular basis, the hot tub becomes watertight. If you find your tub has knots in the wood it may take longer for your tub to become water tight.

If a tub with plastic inner surfaces is leaking, please check:

The Heater for signs of leakage

The Outlet Valve and other possible lead-throughs.

Check the joints and tighten or reattach them carefully.

If these measures do not solve the problem, check how low the water surface of the tub decreases due to the leak and contact our customer service. The easiest way to contact us is by email: The phone number for our technical support is 01748 889303 

Why does Thermowood not shrink and become leaky?

Thermowood swells and shrinks considerably less than untreated wood. Therefore, it does not tend to leak as much as a conventional spruce tubs. 

How should I maintain the outer surface of the hot tub?

Stained, Thermowood and spruce surfaces can be treated with wood oil, provided that they do not form a layer that could damage the panels as the wood swells and shrinks. For Thermowood and stained spruce panels, you can use Teknos Woodex Aqua wood oil with a suitable shade. Composite panels only need to be washed as and when required. Red cedar panels can be treated with paraffin oil.

When treating the tub panels, you can remove the outer hoops or cover them with adhesive tape during treatment, immediately removing any splashes or runoffs. 

Maintenance of your hot tub ensures a longer lifespan. With these stains and oils you can return the hot tub to the original Kirami colour. Stains and oils are both protective and decorative.

A 1 litre tin is sufficient for hot tubs with a diameter of 150cm to 220cm. Oils are only available in 2.5l tins. This will be sufficient for multiple tubs or years of treatment assuming stored in a cool dry place.

Can I treat the inner surface of a wooden hot tub with oil?

We do not recommend treating the inner surface of a wooden tub with oil or other similar substances, as they dissolve into the bathwater when the water is heated.

The outer panels can be treated with various wood oils or stains, both water and solvent-dilutable. In other words, you can use almost any wood treating products sold at hardware stores. 

How should I maintain the inner surface of the hot tub?

We recommend regularly washing the inner surface of your wooden tub with a detergent, rinsing it with water and drying it thoroughly. However, take care not to scrub the inner surfaces too vigorously in order to avoid scratches. 

Plastic lined tubs are more easy to maintain using a cloth and hot soapy water or gentle detergent. However, take care not to scrub the inner surfaces too vigorously in order to avoid scratches

Can I treat the inner surface of a wooden hot tub with oil?

We do not recommend treating the inner surface of a wooden tub with oil or other similar substances, as they dissolve into the bathwater when the water is heated.

The outer panels can be treated with various wood oils or stains, both water and solvent-dilutable. In other words, you can use almost any wood treating products sold at hardware stores. 

What is the service life of the hot tub?

The service life of plastic and aluminium tubs is more than 10 years, but the wooden parts (panels) age/wear over time.

The service life of wooden tubs is approximately 5–10 years, depending on how well it is maintained (washing, oiling and good ventilation). 

Can I use the hot tub in winter?

Yes, you can use your hot tub in winter, provided that you monitor the tub whilst heating it. It is also recommended that you empty the tub after every use in the winter to avoid any water in the tub freezing in harsh winter conditions. 

Be aware when emptying the tub that the surface water could freeze and become a hazard

How should I store the hot tub when it is not being used, e.g. during winter?
  1. You should wash, rinse and dry the tub carefully and make sure that no water is left in the tub/outlet pipe.
  2. You should leave the outlet valves of the tub open for the winter: in rubber-plugged models, the rubber plug should be removed completely.
  3. If the tub has a ball valve, the valve should be opened halfway. This way, any water left in the tub can be drained and the valves will not freeze and break.
  4. You should also remove the filter for the winter and either completely dry it or store it in a warm place.
  5. Store the tub covered.

The heater and the piping will be emptied sufficiently through the outlet valve if the tub has been installed correctly. If there is an extension pipe set installed between the tub and the heater, please ensure that the heater is emptied is also empty of water.

The hot tub has frozen over. What should I do?

If the outlet hose/valve is frozen,

  1. Drain the tub by detaching the heater, enabling you to drain the water through the lower lead-through of the heater.
  2. If the heater is frozen, try thawing it with a fan heater alternately detach the heater and take it inside to thaw.
  3. Never, under any circumstances, light a fire in the heater if you suspect that it is frozen. 
How long can I keep water in the hot tub in winter?

In winter, never leave water in an unused or unheated in the tub, as there is a chance in extreme temperatures the water may freeze. If the water does freeze in the heater and the pipes it will expand and cause damage.

We strongly advise draining the tub in winter months when not in use. Just make sure that the fire and embers have all been extinguished from your heater.

Why does the water smell musty when I remove the tub cover after heating?

When heating your tub, you may find once you remove your cover there is a musty odour. Don't be alarmed this does happen occasionally. Once the cover has been removed the smell should dissipate within 5 minutes.

If you find the odour does not dissipate it maybe you require to change your water or to treat the water with  with some biocool products.

Can I release tub water into the garden?

Generally yes, if you have used BioCool products they are biodegradable. This means that in most cases hot tub water can be drained directly onto the ground;

Please be advised that each municipality has its own regulations for emptying tub water. We therefore recommend that you familiarise yourself with local regulations before emptying your tub.



How can I drain the hot tub of water?

The hot tub features an outlet from which the water is drained through a discharge pipe. it is important when situating your tub that you have thought about the water and where it will go once drained from the tub. If necessary, use a hose to guide the water to where you would like it to run..

Can I use products such as bath fragrances in the hot tub?

You can use bath fragrances and salts in the hot tub, provided that the pH value of the water remains at 7.2–7.6 and you follow the dosage instructions, changes in pH can affect the effectiveness of water treatment methods, leading to potential health risks. 

After using such products, we recommend thoroughly rinsing the inside of the heater. 

How to measure the PH Value of the water.

To measure the pH value of the water use a pH test strip. This is a strip of litmus paper with which you can measure the pH value of a liquid. The substance in the paper causes the paper to show a different colour at different acidities. The official pH scale is from 0 to 14, where 0 is very acidic and 14 very alkaline.

How can I extend the useful life of the tub water?

You can extend the useful life of the water significantly by using a filter and pool chemicals.

Read more about water hygiene with the link provided, please copy and paste into your browser

How often should I change the Hot tub water?

We recommend changing the tub water after one or two days with normal family use. If using the correct filter and chemical use, the water can stay usable for bathing for 1–3 months. You should always use a sanitising chemical if you bathe in the water more than once.

Can I use spring water or sea water in the tub?

Yes you can, as the heater is made of marine grade aluminium. The heaters are protected with galvanic anodes similarly to sea boats and outboard motors. Galvanic anodes protect the heater from corrosion if seawater or maintenance chemicals are used in the tub (In Kirami’s newest heaters, this is implemented with a magnesium anode rod).

All of our hot tubs can be used with spring, sea and lake water. However, we recommend paying special attention to water hygiene when using sea or lake water. If you have any suspicions regarding the cleanliness of the water, you should change the water and clean the hot tub. 

How quickly can my hot tub be heated?

The heating rate of the your hot tub water.

The length of time it takes to heat your tub can vary due to a number of factors.

The power of the heater (powerful heater, fasting heating)

The size of the tub (large tub will take longer that a tub holding less water)

The quality of the firewood (Large, damp wood will have trouble burning and produce little heat)

The air temperature ( A cold external air temp can slow down the heating process)

If the tub covered when heated. (A covered tub, will hold in and build up heat more quickly)

For example, in a 0 °C temperature, a 1,450-litre tub will take approximately 2–3 hours to heat. For heating, we recommend using dry wood chopped into small pieces. Using large and moist firewood may even double the heating time. 


What should I take into account when heating the hot tub?

1. One of the most important things to remember when heating your tub is to ensure the water in your hot tub is covering both filters in your tub. The one in the base of your tub and the one on the inside wall of the tub, please ensure these are immersed in your tub water before igniting any flames in your log burner.

2. Even if you have heated the tub the night before, check the state of the tub anyway.

3. If you want to heat the water as quickly as possible, use dry and high-quality firewood.

4. Using a tub cover shortens the heating time significantly.

5. Empty the heater of ashes before heating, including the top of the grates.

6. Maintain a large fire and add firewood once every 10–15 minutes to make sure that the fire does not go out in the middle of the heating process.

The water is circulated by the force of gravity, meaning that if the fire goes out, the circulation slows down and it takes time to restart the fire and restore the circulation. 

You could accessorise your tub by purchasing a Kirami Mixing paddle this will enable you to stir and agitate the water to ensure the water is heating at an even temperature.

How much wood do I need for heating the hot tub?

Depending on the time of year, heating the hot tub uses around 10 to 20kg of kiln dried birch or mixed hardwood in typical UK conditions. It is essential to ensure that logs are Ready to Burn ie under 20% average moisture content as well as clean i.e. not painted, stained or chemically treated.

For more information about the UK's Woodsure Ready to Burn scheme or to find a local supplier please see the Ready to Burn website. 

The amount of firewood needed varies depending on factors such as the starting temperature of the water, the moisture content and quality of the wood as well as the outside temperature. Below are estimates of how many loads of firewood each heater model consumes.

CULT: approx. 10kg

MACU: approx. 10-15kg

CUBE: approx.  12 to 17kg

TUBE: approx. 15 to 20kg

What kind of wood should I use in a wood-fried hot tub?

The best type of logs to use in your Log Burner are kiln dried birch or mixed hardwood. It is essential to ensure that logs are Ready to Burn ie under 20% average moisture content as well as clean i.e. not painted, stained or chemically treated.

Generally speaking, the higher the density of the wood, the better the heating value, and the most essential factor is the dryness of the firewood.

For more information about the UK's Woodsure Ready to Burn scheme or to find a local supplier please see the Ready to Burn website. 


Can the hot tub be embedded into a terrace?

Yes it can, provided that the heater is placed outside the terrace in a fire-safe area. Be sure to also take water drainage into account when considering the placement.

Installing an extension pipe set and/or a middle outlet set between the heater and the tub may help you to place the tub on a terrace.

A middle outlet set between the heater and the tub may help you to place the tub on a terrace

Read also how to pick a hot tub?


How soon (after the delivery) can I use my hot tub?

Once your tub arrives and has been placed in situ on your ready made foundation. the heater connected, Flue set fitted and safety signs where necessary attached. Steps built for easy access to your tub. Your ready to go.  Just fill your tub with water and light your burner.

We do offer and install service for ease and convenience at a fee, if this helps.


What kind of a surface must the hot tub be placed on?

Choose a flat surface that can withstand the full weight of the tub.

The surface can be evened out with stone chippings with a roughness from 6-16 mm, for example. If you want to have a more solid foundation, you can cast one from concrete or use ready-made slabs. It is also recommended to keep the surrounding area of the tub free of vegetation. See instructions!

You should place drains on the foundation of a wooden tub in order to keep the bottom of the tub sufficiently dry and prevent rot. 

Can the hot tub be transported on its side?

We do not recommend rolling your tub or transporting the hot tub on its side.

The tub must be moved from place to place in the upright position.

The brim of the tub cannot withstand the weight of the tub will compromise the strength and shape of the tub. 

How can I move the hot tub?

Hot tubs are primarily delivered with all accessories packed inside it, whereby the weight of the package can exceed 200 kg.

Once tub is delivered remove the accessories from inside the tub to make the tub a more manageable weight.

The tub itself is relatively light, so once you remove the heater and other loose parts the remaining weight will be between 100 to 160 kg depending on the model, meaning that the tub can be carried by 3–4 people.

Please remember the tub should not be rolled or transported on its side. It must be carried upright at all times.

Can I have my tub delivered to somewhere other than my home?

Yes and we cover the whole of the UK at least once per month, sometimes up to once per fortnight. If we can fit your delivery in to an existing route we will.

Can I return my hot tub if I'm not happy?

Yes of course- our customers have the right to cancel their order at any time before the hot tub is despatched or within 30 days of receiving it.

The Hot Tub must be in unused and still in the original packaging.

The refund given will exclude the cost of delivery and cost of returning the goods to us.  The return may be done either via a courier, pallet service or collection by one of our own vehicles. 

When will I get my hot tub/sauna?

We stock a large quantity of new and preloved wood-fired hot tubs in our UK warehouse which enables us to be able to supply our customers in a very reasonable time frame. Our deliveries cover the whole of the UK at least once per month, sometimes up to once per fortnight. 

Unlike many other retailers, we use our own UK based staff and vehicles to deliver and install throughout the UK. 

On some occasions we may need to place an order with the Kirami factory in Finland which would incur a short delay in delivery, typically by only 3 to 4 weeks.  

We are very happy to discuss this with you before you place your order.