How to install a sauna heater
Updated: 21 October 2026
You can usually bolt a bracket and stack stones. You cannot treat these heaters as a plug-in appliance. This guide on how to install a sauna heater splits the job between what you can prepare and what a competent electrician designs, connects, tests, and certifies. It follows the seven listings in our [sauna heater comparison](/hub/steam-baths/sauna-heater). None of the electric rows includes a 13 A plug. The Products Compared editorial team read the listings and public UK installation explainers. We are not describing how to terminate conductors, and we are not giving you a breaker size. A qualifying purchase through our links can earn a commission at no extra cost to you. Do not switch the heater on until the circuit has an Electrical Installation Certificate.
You can usually bolt a bracket and stack stones. You cannot treat these heaters as a plug-in appliance.
You can usually bolt a bracket and stack stones. You cannot treat these heaters as a plug-in appliance. This guide on how to install a sauna heater splits the job between what you can prepare and what a competent electrician designs, connects, tests, and certifies. It follows the seven listings in our sauna heater comparison. None of the electric rows includes a 13 A plug. The Products Compared editorial team read the listings and public UK installation explainers. We are not describing how to terminate conductors, and we are not giving you a breaker size. A qualifying purchase through our links can earn a commission at no extra cost to you. Do not switch the heater on until the circuit has an Electrical Installation Certificate.
Our top picks
| Badge | Product | Plug or flue | Supply | Stones or water | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Mxmoonant Mxmoonant 6 kW digital sauna heater | Plug not included | 215–240 V and 380–415 V | 18–20 kg stones, not included | 8.2 | about £297.00 | View offer |
| Alternative |  CGOLDENWALL CGOLDENWALL 4.5 kW steam generator | Not stated | 220 V field; pattern field 380V | Water tank; self-draining claimed | 6.7 | about £426.54 | View offer |
| Best value |  Mxmoonant Mxmoonant 6 kW sauna heater | Plug not included | 215–240 V and 380–415 V | 14–18 kg stones, not included | 7.6 | about £269.00 | View offer |
On this page
What you can do before anyone wires it
Start with the manual and the wall, not the consumer unit. On a stone stove you can check that the bracket matches the stated body, clear the floor line the listing gives, and buy the stones the notice asks for. The Mxmoonant WS-37-WJY states a body of 48 x 34 x 57 cm and 13.56 kg, and it asks for 18–20 kg of stones that are not in the box. The Anjur states about 18 cm from the ground and 20 kg of stones, also extra. A UK review of the WS-15-WJY describes an install in under 20 minutes, which is a mounting claim, not evidence that the circuit was finished in that time.
Steam units add a water path you can plan and not energise. The CGOLDENWALL box list names a nozzle, a drain valve, and a safety valve. The Caiqinlen listing does not state a drain. If the manual is missing, you do not invent a wiring method from the title.
That is the end of the owner’s list. The notices on both Mxmoonant pages say there is no plug and that a licensed electrician should do the wiring. Hand over the data plate, the diagram, and the room band. Criteria for whether you should have ordered this listing at all are on the sauna heater buying guide.
What the electrician owns
A 6 kW heater is not a socket load. SaunaShop’s shop method divides watts by 230, which puts 6 kW at about 26 A. Above about 8 kW, the same shop page says a domestic heater is usually three-phase. Use that only as a reason to book the electrician. Do not turn 26 A into a fuse rating or a cable cross-section for these ASINs. A review from France on the WS-37-WJY says a 16 A supply stopped the heater after about five minutes, and that the later install used a 32 A breaker and 6 mm² cable. That is experience on one job. It is not the specification printed for your house.
The circuit is new, dedicated, and tested. In England and Wales, Approved Document P makes certain electrical work notifiable to building control, and a sauna-heater room is treated as a special location. You should come away with a certificate, not a forum screenshot of someone else’s consumer unit. Scotland and Northern Ireland are not under Part P. They use their own building rules, so the question to the electrician is which regime applies at your address. Controls belong outside the hot room. Explainers such as Sandwich Electrical and Elec-Mate agree on a dedicated supply and on switches you can reach without standing in the heat. They do not agree on whether the heater itself sits on an RCD. Leave that disagreement with the manual and the person signing the certificate.
Heat inside the room
Ordinary grey flex is the wrong material once the air is at sauna temperature. Installer Online’s account of BS 7671 section 703 puts the heater alone in zone 1, and it puts zone 3 equipment at 125°C and the cable at 170°C. Sandwich Electrical talks about silicone cable rated around 170°C inside the room, and about an Electrical Installation Certificate. Their zone letters A, B, and C are not the same labels as zones 1 to 3. Do not draw their letters onto the regulation diagram.
The listing still has to give clearances. The Anjur’s “about 18 cm from the ground” is one printed line. If the manual’s gap to the bench, the wall, or the sensor is missing, the electrician cannot invent it, and you should not either.
The room volume that drove the kilowatt choice is a separate sum. If you have not checked the glass door against the listing’s own band, do that on the sauna heater size calculator before anyone orders cable.
Steam and the wood stove are different jobs
A steam generator needs water in and a way for water to leave, as well as a cable. Homebuilding’s bathroom guidance makes the same split: a traditional sauna needs a dedicated supply and does not need a plumbed feed for the ladle you pour on stones, while a steam generator needs a water supply and a drain. The CGOLDENWALL includes a drain valve. An Italian review says the safety valve vented about 15 minutes after switch-off, which is a reason to know where that valve discharges, not a reason to cap it. The Caiqinlen does not state a drain on the listing, so you confirm it in the manual before the enclosure is tiled shut.
The voltage clash on the CGOLDENWALL (220 V in one field, 380V in another) and on both Mxmoonant notices (single-phase and three-phase) is the electrician’s first question, not a jumper you choose on the day.
The WILLOWYBE stove10 is not this electrical job. It is a 16 kg wood stove for an outdoor tent, with a flue, and the file does not show a Defra exemption. Reviews describe smoke and a chimney joint that stopped drafting. Keep the fire and the flue outdoors. Until the certificate exists, the heater stays off.
Common questions
Can I plug a 6 kW heater into a wall socket?
No. A UK socket is 13 A, and SaunaShop’s method puts 6 kW at about 26 A. Both Mxmoonant notices say the plug is not in the box. The connection is an electrician’s circuit, not a 13 A lead.
What am I allowed to do before the electrician comes?
You can check the bracket, the clearances in the manual, the stones you still have to buy, and, on a steam unit, that a drain path exists. You do not energise the heater, choose a breaker, or terminate the cable.
Is the work notifiable where I live?
In England and Wales, new circuit work in this kind of room is the Part P question for your electrician, and you should expect a certificate. Scotland and Northern Ireland are outside Part P and follow their own building rules.
Why is ordinary grey cable a problem inside the room?
Section 703, as Installer Online summarises it, expects cable in the hot zone to cope with about 170°C, with equipment at about 125°C. Ordinary PVC flex is not that cable. The electrician specifies it. This page does not.
Does a steam generator need a drain as well as a cable?
Yes if you want the condensate and the safety valve to have somewhere to go. The CGOLDENWALL includes a drain valve. The Caiqinlen listing does not state one, so you confirm it before the room is closed up.
What if the listing shows 220 V and 380 V?
You stop and let the electrician match the data plate to the supply. The CGOLDENWALL prints both, and both Mxmoonant notices print single-phase and three-phase. Do not pick one from the title.
Related pages
Sources
Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk figures saved for this set on 20 October 2026.
- Harvia, how to select heater power (retrieved 20 October 2026)
- SaunaShop FAQ (retrieved 20 October 2026)
- Installer Online, electrical requirements for sauna cabins (retrieved 20 October 2026)
- Approved Document P (GOV.UK) (retrieved 20 October 2026)
- IET, Part P frequently asked questions (retrieved 20 October 2026)
- NBS, BS EN 60335-2-53:2011+A11:2023 (retrieved 20 October 2026)
- NHS Collingwood Surgery, sauna or jacuzzi in pregnancy (retrieved 20 October 2026)
- Defra, smoke-exempt appliances (retrieved 20 October 2026)