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Best greenhouse heater UK

Updated: October 2026

You have nine greenhouse heaters on one amazon.co.uk shelf and you want one name, plus a cheaper tube that is honest about what it cannot heat. The best greenhouse heater UK in this set has to show a UK voltage and a control that is more than an overheat cut-out. Price and best-seller rank do not replace either. This page is allowed to choose. The [greenhouse heater comparison](/hub/raised-beds-greenhouses-and-compost/greenhouse-heater) still shows every listing. Products Compared read the captured listings and public RHS guidance. There was no laboratory test. A qualifying purchase can earn a commission at no extra cost to you.

You have nine greenhouse heaters on one amazon.co.uk shelf and you want one name, plus a cheaper tube that is honest about what it cannot heat.

Our top picks

Airmaster Airmaster FW400 frost-watch

Best overall

Airmaster Airmaster FW400 frost-watch
8.6/10about £25.94
View offer
Hylite Hylite 300 mm 28 W tube

Best value

Hylite Hylite 300 mm 28 W tube
8.2/10about £23.49
View offer
Trendi Trendi 4.5 L paraffin heater

Rank 3

Trendi Trendi 4.5 L paraffin heater
7.4/10about £18.95
View offer
On this page
  1. 1.What a pick has to show
  2. 2.Top pick in this set
  3. 3.Best value in this set
  4. 4.Who is not the pick

What a pick has to show

A pick in this file needs 230 V or 240 V in the specification, and a thermostat that states degrees rather than only a cut-out. An IP line is useful in a damp house, and it is still only a claim. The RHS treats a fan as the higher-output option that moves air, and a tube as lower-energy background heat. It also says the fan should be one sold for greenhouses, and that you should not wet the heater. Rank in Greenhouse Heaters is a sales position, not a test. A 120 V field fails even with that rank. A missing voltage fails until you can read the plate. A 90° cut-out is not a frost dial. The Airmaster clears voltage and a degree band together. The 300 mm Hylite clears voltage and a low price, with a thermostat claim that reviews say has no scale.

Top pick in this set

The top pick is the Airmaster FW400, ASIN B07NKSJBYG, at £25.94. It states 520 W at 240 V and 2.17 A, a thermostat of 5–30°C. One UK review used it for a night in a 6 × 8 when it was near freezing outside. Skip it if you need a stated IP rating. This file has none, and the RHS says not to wet the heater. Another review says the booklet limits the heater to well insulated spaces or occasional use. That is the reviewer’s report of the booklet. Two Wests prints about 1,170 W bare and about 936 W insulated for frost protection on a 6 × 8. 520 W is below both, so this is the best control in the set, not a replacement for insulation. There is no timer in the specification block.
Airmaster Airmaster FW400 frost-watch

Testsieger

Airmaster Airmaster FW400 frost-watch
8.6/10about £25.94
View offer

Best value in this set

The best value is the Hylite 300 mm tube, ASIN B00TFHBEDG, at £23.49. It states 28 W at 230 V and 0.12 A, claims IP44, a thermostat and automatic shut-off, and includes a 1.5 m cable and plug. UK reviews call the thermostat crude. There is no degree scale in the file. At full output, 28 W is about 0.7 pence an hour on Ofgem’s 26.32 p/kWh rate for 1 October to 31 December 2026, which is why it is the value pick for a small volume and not for a 6 × 8. The LightHouse at £22.99 states 230 V and has no thermostat, and the title says 45 W while the spec field says 50 W. Skip the 28 W tube for a cold-snap 6 × 8, for a printed scale, or if you would change a fuse from a review when the listing states none.

Who is not the pick

The AC Infinity THERMOFORGE S7 at £89.99 states 120 V and 8.33 A. Rank 19 in Greenhouse Heaters does not make 120 V a UK heater. The AAOBOSI at £119.99 is 2,000 W with a stated 5–42°C band, and the file does not state voltage. Reviews are rooms and workshops more often than greenhouses. The Trendi at £18.95 is the only paraffin heater, with no thermostat. The 4,500 W field is not a measured output, and UK reviews mention smoke and soot on plants. Cheapest hardware is not best value beside a working socket.

Common questions

Which listing is the top pick, and who should skip it?
The Airmaster FW400 at £25.94, 520 W, 240 V, with a stated 5–30°C thermostat. Skip it if you need an IP rating in the file, if the booklet limit reported in a review rules out your house, or if you are sizing an uninsulated 6 × 8 from the Two Wests watt table. One overnight review in a 6 × 8 is not a winter trial.
Which listing is the best value, and who should skip it?
The Hylite 300 mm 28 W tube at £23.49, stated at 230 V, with 4.1 from 2,276 reviews. Skip it for a whole 6 × 8, for a printed degree scale, and if you would change the fuse from a review rather than from the maker’s instructions. The listing does not state a fuse.
Why is the cheapest tube not automatically the best value?
The LightHouse at £22.99 states 230 V and costs less than the Hylite, and it has no thermostat. The title and the spec field also disagree (45 W and 50 W). Best value here means a low price with a stated UK voltage and a thermostat claim you can live with, not the smallest sticker.
Why is the 120 V heater out?
The AC Infinity specification block says 120 V and 8.33 A. A UK socket is nominal 230 V with a BS 1363 plug. The reviews stored with that file are not United Kingdom headers. Greenhouse Heaters rank does not change the voltage.
Why is the 2,000 W Wi-Fi heater not the top pick?
The AAOBOSI states 2,000 W and 5–42°C, and it does not state mains voltage. Reviews in the file are mostly indoor rooms and workshops, and some dispute whether it holds a mild set point. Output that high is also about 53 pence an hour at the Ofgem rate if it runs flat out.
Is the paraffin heater the best value because it is £18.95?
No. The Trendi has no thermostat, fuel is extra, and UK reviews mention smoke and soot. The 4,500 W line is not a watt test. It is the no-socket option in this set, not the value pick beside a working socket.

Related pages

Greenhouse heater buying guide

Greenhouse frost protection heater

Electric or paraffin greenhouse heater

Greenhouse heater

How to use a greenhouse heater: place, dial, check

Sources

Public UK sources from the research digest, last checked on 17 October 2026.

  1. RHS — Heating greenhouses efficiently (retrieved 17.10.2026)
  2. RHS — Electricity in the garden (retrieved 17.10.2026)
  3. Ofgem — Energy price cap, 1 October to 31 December 2026 (retrieved 17.10.2026)
  4. Approved Document P (2013) (retrieved 17.10.2026)
  5. Electrical Equipment (Safety) Regulations 2016, regulation 35 (retrieved 17.10.2026)
  6. NHS — Carbon monoxide poisoning (retrieved 17.10.2026)
  7. Two Wests — Greenhouse heaters (retrieved 17.10.2026)
  8. Hylite — Greenhouse heater data sheet (retrieved 17.10.2026)