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15 kW heater for a garage

Updated: October 2026

You want a 15 kW heater for a garage or a small workshop, and the titles already say garage. A car or a petrol can in that space is where the titles and the guidance part company. In this set the heater is either a 400 V electric blower or a propane blower that still needs a socket. Only the electric one keeps combustion products out of the room. The [15 kW fan heater comparison](/hub/portable-heaters/15kw-fan-heater) lists the four models. Hourly cost is on the [electric or gas](/hub/portable-heaters/15kw-fan-heater/sub/15kw-fan-heater-electric-or-gas) page. Figures are from the listings and public UK guidance on 15 October 2026.

You want a 15 kW heater for a garage or a small workshop, and the titles already say garage. A car or a petrol can in that space is where the titles and the guidance part company.

Our top picks

DAHTEC DAHTEC IFHO3-150G black

Best overall

DAHTEC DAHTEC IFHO3-150G black
5.2/10about £186.15
View offer
DAHTEC DAHTEC BGA1401-15-18 gas

Alternative

DAHTEC DAHTEC BGA1401-15-18 gas
4.4/10about £84.15
View offer
ALINI ALINI ALINI15GH propane

Best value

ALINI ALINI ALINI15GH propane
4.9/10about £75.99
View offer
On this page
  1. 1.What the listings say a garage is for
  2. 2.Flueless gas, petrol vapour, and the 100 square metre note
  3. 3.A workshop that already has 400 V
  4. 4.A small garage with only a normal socket

What the listings say a garage is for

Every kept listing puts a garage in the title or the recommended uses, and every usage field still says Indoor. The electric IFHO3-150G lists a garage and workshops, at £186.15, on 400 V. The DAHTEC gas blower at £84.15 lists a garage and a warehouse. The ALINI at £75.99 says garage and workshop. Indoor plus garage is the wording on the page. It is not a check that your garage has the vents. A UK single garage is often far smaller than 100 square metres.

Flueless gas, petrol vapour, and the 100 square metre note

Calor’s guidance on mobile gas heaters is to keep one out of a garage where petrol vapour may be present. The Health and Safety Executive treats LPG in enclosed spaces as a carbon monoxide risk: keep high- and low-level vents clear and leave grilles uncovered. Baron Bratby wrote on 5 October 2026 that the DAHTEC gas instructions required at least 100 square metres, and that his double garage of about 65 square metres was below that, so he sent it back. That 65 square metre figure is his estimate. Gas work covered by the Gas Safety (Installation and Use) Regulations 1998, in England, Wales and Scotland, belongs with a Gas Safe registered engineer. If the room smells of petrol, leave the propane rows.
DAHTEC DAHTEC IFHO3-150G black

Testsieger

DAHTEC DAHTEC IFHO3-150G black
5.2/10about £186.15
View offer

A workshop that already has 400 V

The electric pair is the workshop fit when the outlet is already 400 V three-phase and you want dry heat. Black ASIN B0FFYMDQZ5 and silver ASIN B0FFY14ZKQ are both IFHO3-150G at £186.15, 14.5 kg, with steps of 95 W, 5 kW, 10 kW and 15 kW. There is no bottle in the room. Overheat protection is stated, and the plug on the 1.60 m lead is unnamed. If the outlet is not there yet, stop. A new circuit in a dwelling in England is notifiable under Approved Document P. Once the outlet is real, the start sequence is on the how to use page.

A small garage with only a normal socket

A domestic garage with a BS 1363 socket and a closed door is the case these titles handle badly. The electric heater will not run on 220–240 V. The propane heaters are what the titles offer, and what the petrol-vapour guidance and the 100 square metre note argue against. Electrical Safety First’s ceiling for a 13 A fuse is about 3 kW. The plug-in fan heater comparison is the route for that socket. If anyone feels unwell, if you smell gas, or if a carbon monoxide alarm sounds, switch off, get fresh air, and leave it off.

Common questions

Can I run the gas 15 kW heater in a domestic garage?
Plan on no when petrol vapour may be present, which is the usual garage with a car or a petrol can. Calor’s mobile-heater guidance and the HSE carbon monoxide note both point away from a flueless LPG heater there. The listings still say garage and Indoor. The instruction minimum still applies.
What did the DAHTEC gas instructions say about room size?
Baron Bratby wrote on 5 October 2026 that the instructions required at least 100 square metres, and that his double garage, about 65 square metres by his estimate, was too small, so he returned the heater. The bullets do not print that 100 square metre line. Read the sheet in your box.
Is an electric 15 kW heater allowed in a workshop?
It can be the right workshop heater when the supply is 400 V three-phase and the equipment suits the place. The IFHO3-150G states that supply, forbids a household socket, and lists workshops, with the usage field set to Indoor. Overheat protection is stated. The plug type is not. At work, the Electricity at Work Regulations 1989 still ask for suitable equipment.
What if the workshop only has 13 A sockets?
Then none of these four is the match. The electric model is barred from 220–240 V by its own bullets. The gas models still want a mains fan and a room that may take propane without petrol vapour. About 3 kW is the Electrical Safety First ceiling for a 13 A fuse.
Do I need Gas Safe to connect the hose?
A hose the instructions already specify is a different job from opening the burner. Gas work the 1998 regulations cover is for a Gas Safe registered engineer in England, Wales and Scotland, not under that instrument in Northern Ireland. If the thread will not fit, stop. The ALINI lists its regulator and 1.5 m hose.
What do I do if the room feels stuffy or someone feels unwell?
Switch the heater off, open the space, and keep it off. The HSE note on LPG in enclosed spaces is about carbon monoxide, clear high- and low-level vents, and grilles left uncovered. If you smell gas, or a carbon monoxide alarm sounds, leave the heater off and get help. The electric model removes the burner. It still needs a supply that matches 400 V.

Related pages

15 kW fan heater buying guide

15 kW fan heater

Best 15 kW fan heater UK: which listing should you buy

15 kW electric or gas heater: hourly cost compared

How to use a 15 kW fan heater before you switch on

Sources

Public UK sources for supply, gas safety, and the hourly arithmetic. Listing prices, stars, and review counts are from amazon.co.uk on 15 October 2026.

  1. HSE — Electrical equipment at work (retrieved 15 October 2026)
  2. HSE HSR25 — Memorandum of guidance on the Electricity at Work Regulations 1989 (retrieved 15 October 2026)
  3. HSE — Carbon monoxide in construction (retrieved 15 October 2026)
  4. Gas Safety (Installation and Use) Regulations 1998 (retrieved 15 October 2026)
  5. Approved Document P — Electrical safety in dwellings (retrieved 15 October 2026)
  6. Ofgem — Energy price cap, 1 October to 31 December 2026 (retrieved 15 October 2026)
  7. Electrical Safety First — Plugs and fuses (retrieved 15 October 2026)
  8. Calor — LPG bottle prices (retrieved 15 October 2026)