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Sauna heater or steam generator: same 9 kW, different room

Updated: October 2026

You searched for a 9 kW sauna and amazon.co.uk has put a stone stove and a steam kit in the same row of results. A sauna heater or steam generator decision is a temperature decision. A Finnish room is a hot space where you can throw a little water on stones. A steam generator fills a sealed cubicle with vapour and, where a cap is printed, stops around 35–55°C. Nine kilowatts does not close that gap. Our [9 kW sauna heater comparison](/hub/steam-baths/sauna-heater-9kw) keeps both types because both were on the shelf on 20 October 2026. A qualifying purchase can earn a commission at no extra cost to you.

You searched for a 9 kW sauna and amazon.co.uk has put a stone stove and a steam kit in the same row of results. A sauna heater or steam generator decision is a temperature decision.

Our top picks

Harvia Harvia Spirit SP90XW 9 kW

Best overall

Harvia Harvia Spirit SP90XW 9 kW
5.4/10about £990.00
View offer
CGOLDENWALL CGOLDENWALL 9 kW steam kit

Alternative

CGOLDENWALL CGOLDENWALL 9 kW steam kit
7.8/10about £350.55
View offer
Generic Generic 9 kW stone heater

Best value

Generic Generic 9 kW stone heater
3.0/10about £245.00
View offer
On this page
  1. 1.The temperatures are not the same scale
  2. 2.What you install
  3. 3.Which listings are which
  4. 4.When to choose which

The temperatures are not the same scale

SPATA puts a sauna usually above about 80°C, with humidity often around 5–20%, and a steam bath up to about 45°C at about 90–100% humidity. C.P. Hart’s home guide puts a Finnish sauna at about 70–100°C and low humidity, with water on the stones as a short burst, and a steam room at about 40–45°C with saturated air. Those two descriptions overlap each other. They do not overlap a listing that stops at 55°C. The CGOLDENWALL kits and the Hanchen print 35–55°C. The £245.00 stove prints a knob up to 90°C, and the £559.99 stove prints up to 110°C. A steam generator on those pages will not run an 80°C wooden sauna. The KXJQBM page prints no temperature.

What you install

A stone heater sits in the hot room, or on its wall, and it needs rocks. The £245.00 listing says 14–20 kg of stones are extra. The £559.99 listing says 10–20 kg are extra. The Harvia Spirit page does not say the stones are included. Water on those stones is a brief burst. That ladle is not a steam generator, and it does not hold shower-level humidity for an hour. A steam generator sits outside the cubicle and pushes vapour through a steam head. The older CGOLDENWALL box lists the generator, a steam head, a control cable and a probe. The ST-90 adds a drain valve and a safety valve. The Hanchen’s automatic water system is sold separately. You also need a sealed enclosure and a fall to a drain.
Harvia Harvia Spirit SP90XW 9 kW

Testsieger

Harvia Harvia Spirit SP90XW 9 kW
5.4/10about £990.00
View offer

Which listings are which

Three of the seven listings are stone heaters. The Harvia Spirit SP90XW at £990.00 is a Finnish sauna oven with a claimed WiFi panel, and its table leaves temperature blank. The generic wall stove at £245.00 has a 90°C knob and a stated 9–13 m³ band. The generic digital stove at £559.99 has a stated limit of 110°C and a 200–240 V line. Wet and dry on a stone-stove title means you can ladle water onto stones. It does not mean a 45°C steam generator. The steam rows are the two CGOLDENWALL kits, the Hanchen and the KXJQBM. Both CGOLDENWALL pages state 8.5 m³ and 35–55°C. The Hanchen states within 7.5 m³ at 380 V. The KXJQBM is titled 380 V with no room and no temperature. Cubic metres are on the room-size guide.

When to choose which

Choose a stone heater if the room has to reach sauna temperature, in the 70–100°C band C.P. Hart describes or above the roughly 80°C line SPATA uses, and if your volume sits inside that heater’s own minimum and maximum. The £245.00 stove is the cheap end, with no reviews and with stones extra. The Harvia is the named end, with voltage and room volume missing on the listing. The £559.99 stove prints 200–240 V and still uses a family-wide room line. None of those gaps changes the type. Choose a steam generator if the room has to fill with vapour around 40–55°C and the voltage matches the house. The 220 V CGOLDENWALL kits are the plausible supply. Leave the Hanchen and the KXJQBM until an electrician has confirmed 380 V. The temperature cap is the product.

Common questions

Is a steam generator a sauna heater?
No. In this set a sauna heater is a stone stove for a hot room, and a steam generator is a vapour unit for a sealed cubicle. SPATA put sauna heat usually above about 80°C and a steam bath up to about 45°C. The CGOLDENWALL and Hanchen pages print 35–55°C. A shared 9 kW figure does not make them interchangeable.
Can I pour water on a steam generator?
A ladle of water goes on sauna stones, for a short burst, in the way C.P. Hart describe a Finnish sauna. A steam generator makes the vapour itself and sends it through a steam head. The £245.00 and £559.99 stoves talk about stones. The steam kits talk about heads, probes and drains.
What does wet and dry mean on the cheap stove?
On the £245.00 stone stove, wet and dry means a hot room that can take water on the stones. The page still states a knob up to 90°C and a 9–13 m³ band. It does not state 35–55°C, and it does not include a steam head. Treat wet as a ladle, not as a steam-shower generator.
Which of the seven listings are stone heaters?
The stone heaters are the Harvia Spirit SP90XW at £990.00, the generic wall stove at £245.00, and the generic digital stove at £559.99. The steam generators are the two CGOLDENWALL kits, the Hanchen and the KXJQBM. The Harvia page does not print a temperature, but it is sold as a sauna oven, not as a 35–55°C generator.
Do I need a drain for steam?
A steam cubicle needs a way for water to leave. The newer CGOLDENWALL lists a drain valve and a safety valve in the box. The Hanchen sells the automatic water system separately. A review on the older kit reports a drain that failed, so a drain on the specification is not a drain that lasts.
Will 9 kW of steam feel like 9 kW of sauna?
No. The kilowatts are the electrical load. Steam at 35–55°C is a different session from a sauna above about 80°C with humidity often around 5–20%, which is SPATA’s split.

Related pages

9 kW sauna heater buying guide

Best 9 kW sauna heater

Sauna heater 9kW

9kW sauna heater installation: the circuit, not a plug

What size sauna heater 9kW: measure the room first

Sources

Public UK sources named below, taken from the research digest first. amazon.co.uk prices on these seven listings were taken from the listings, shelf date 20 October 2026. Page updated October 2026.

  1. GOV.UK: Electrical Equipment (Safety) Regulations 2016 (retrieved 20 October 2026)
  2. Approved Document P (England) (retrieved 20 October 2026)
  3. Consumer Rights Act 2015, section 22 (retrieved 20 October 2026)
  4. NBS: BS EN 60335-2-53:2011+A11:2023 (retrieved 20 October 2026)
  5. Harvia: how to select heater power (retrieved 20 October 2026)
  6. Harvia Spirit European manual (retrieved 20 October 2026)
  7. Elec-Mate: sauna electrical installation (retrieved 20 October 2026)
  8. SPATA: sauna and steam factsheet (retrieved 20 October 2026)