10 Best Greenhouse Heaters Reviews UK 2020 - Top-Rated Models Compared

Last Updated on September 8, 2020

In this article, we have rounded up the best greenhouse heaters you can buy today. A greenhouse can be an idyllic retreat in even the smallest of places. This miniature paradise is incredibly sensitive, though. If the temperature suddenly plummets, you can forget those baby strawberries.

You do not have to spend a fortune on heaters for greenhouses, and we've done all the leg work for you. So sit back, relax and check out our top 10 best greenhouse heaters.

Greenhouse Heaters Reviews

Best Greenhouse Heaters On The UK Market Reviewed In 2020

Plainly the brand says it all! The SHTTH2 by Sunhouse is one of the best greenhouse heaters we reviewed. This tubular heater will provide safe and consistent heat to help ensure that your prized harvest does not suffer.

This small greenhouse heater measures just 71 cms and is designed for continuous operation. This truly is a set it and forget device. This greenhouse heater has a built-in thermostatic control. It uses an intelligent power cycle to conserve energy. When initially turned on, it will take a few minutes to warm up. Once warmed up, the unit will then heat the environment in bursts. It also features a heat cutoff to prevent this unit from overheating and causing a fire.

Got a leaky roof? No need to worry. The SHTTH2 is splash-proof to IPX4 standard. The heater is fitted with an adjustable thermostat which allows the user to control the heat output. If you just want to prevent frost, then you can set this greenhouse heater at its lowest setting.

sunhouse-shtth2-80w-tubular-he

Pros

  • Small Design
  • Thermostatic Control
  • Only 80w

Cons

  • Multiple units needed for medium space
  • Only splashproof, not waterproof

The Dimplex ECOT range of thermostatic tubular heaters is an ideal choice of heating for greenhouse. Much like the previous heater we reviewed, this is suitable for applications which require safe, low-wattage background heating for localised frost protection.


We also had some success with using it as a window demister and a way to prevent damp in cupboards.

dimplex-ecot2ft-tubular-heater

This is probably the best greenhouse heater in terms of thermostatic control. The ECOT has six variable heat output settings. This allows you to have much more precise control over the temperature your bell peppers endure. When compared with cheap greenhouse heaters that use paraffin fueled heating element, the accurate temperature control becomes a valuable feature.

Discreet mounting brackets for walls or floors are included, and the cable entry is reversible left or right which offers you the freedom to install this wherever you like. This heater does, however, have to be installed horizontally. As you would expect, it includes a thermal overload cutout for safety and is fully splash-proof (IPX4 rated). A range of guards is also available to fit these tubular heaters.

Pros

  • Available in 1ft or 2ft
  • Precise thermostatic control
  • Reversible cable entry

Cons

  • Must be mounted horizontally not vertically
  • Only splashproof, not waterproof

Hausen is a reputable brand, and they do not disappoint with number three on our best greenhouse heaters list. This greenhouse heater comes in four sizes from 1ft to 4ft with respective wattage of 60w to 240w. They are also remarkably affordable, given their quality and recognisable brand name.

Hausen has outdone the competition and this greenhouse heater is not only splash-proof but completely IP55 waterproof.

hausen-electric-tubular-heater

Although confusingly, the manual states, "not suitable for use outdoors in damp weather, in bathrooms or in other wet or damp environments." This units safety system is two-tier. It has two levels of thermal protection the first is when the unit reaches 90°c at which point it lowers its output; if this electric greenhouse heater with thermostat ever reaches 130°c, then it switches off. This heater comes with a generous 1.5m cable.

Pros

  • Available in 4 sizes from1ft to 4ft
  • Fully Waterproof
  • 1ft heater uses just 60w
  • Two-tier thermal cutout

Cons

  • A fixed cable entry point
  • Confusing manual

Ok so this unit from Srendi may not be the pinnacle of technology, but it is efficient and looks quite unique. This is a twin Chimney Paraffin Heater. Srendi recommends that this is the best greenhouse heater for greenhouses up to 6' x 6'.

This is possibly the best paraffin heater for greenhouse. Its large capacity 5-litre tank will burn for up to 40 hours on one fill. Srendi hasn't scrimped on quality here either; it has threaded chimneys, brass plated twin burners in each chimney and a flame extinguisher.


Twin chimneys seem to be rarer on Paraffin heaters than their single chimney counterpart. There does not seem to be any discernable difference in their power output, and so this might just be an aesthetic consideration.

srendi-large-paraffin-super-wa

Pros

  • Puts out a lot of heat
  • No electric bill

Cons

  • Lack of safety cutout
  • No temperature control

This entry by Lighthouse is perhaps the best greenhouse heater for those slightly larger greenhouses. This unit will help keep your greenhouse frost free with its 135w heating element. This glasshouse heater will provide a stable environment, protecting plants against sudden temperature and humidity fluctuations.


This is the best heater for those who want a balance between power output and efficiency. With its 135w thermostatically controlled output, it is very cost-effective.

lighthouse-915mm-135w

This electric tube heater uses less than 50w per foot which is similar to an ordinary light bulb and 25% less than most similar tube heaters. It may not be the most feature-rich device, but it is easy to use and will heat your plants and is possibly the cheapest greenhouse heater to run.

Pros

  • Digital thermostat
  • Very energy efficient
  • Easy to use

Cons

  • Not suitable for a large greenhouse
  • Only one wattage/size available

This is our first greenhouse gas heaters review. Unlike your standard greenhouse electric heater, this particular device runs off propane. This entry by Greenhouse Warehouse is quite unique because unlike the Paraffin heater we reviewed earlier, this device has a built-in thermostatic control and built-in piezo ignition.


The glasshouse heaters we have reviewed so far have had power outputs in watts. This unit has variable heat settings that max out at a whopping 2kw!

Encased in a durable green coated stainless steel casing, this unit is sure to survive many winters and months stored at the back of your shed. This unit pumps out heat but will cost a little more money to buy; gas is however usually cheaper than electric per kw.

This greenhouse heater is ideal for an 8x6ft greenhouse. This little green pal will keep your plants protected and keep your greenhouse frost free. Comes complete with 1m of hose, two clips and a Propane regulator

lifestyle-greenhouse-heater

Pros

  • Puts out a maximum of a massive 2kw
  • Non-electric
  • thermostatically controlled

Cons

  • Recommended you use a CO2 detector
  • Much larger than a tube heater

This greenhouse heater, by Simplicity, was first launched in 2019. It now features an external and more precise thermostat probe. Desired temperatures are now also listed on the dial. Unlike our electric greenhouse heaters review for tube heaters, this unit also uses a fan. This means that it does not rely on existing circulation in your greenhouse. This electric heater will ensure even heat dissipation throughout your greenhouse to keep all your plants comfortable.

The strong metal casing is powder-coated in attractive Anthracite colour and will outperform the plastic cases of rival heaters. Inside is a stainless steel heating element. This model is IPX4 rated, which means it is splashproof, so leaky roofs and the odd bit of water are fine. You can use this heater as a fan only (in summer), or you can set the switch to 1kW heat or 2kW heat output depending on how big your greenhouse is.

simplicity-2kw-greenhouse-fan-

The manufacturer recommends that you use the heater in conjunction with a max-min thermometer in your greenhouse, to help you fine-tune your setup. It is quite refreshing to see this recommendation as it demonstrates that Simplicity knows what they are talking about. It gives us a warm and fuzzy feeling... we couldn't help it.

As always, we are often asked what size greenhouse this heater will heat? As a general guide, 2kW electric heaters will heat up to an 8x12 greenhouse, possibly a little bigger if you only want it frost-free. Simplicity also sells a 3kw model for larger greenhouses and barns. This is probably the best electric greenhouse heater we have reviewed due to its output and features; Simplicity really has out a lot of thought into this.

Pros

  • 1kw and 2kw heating mode
  • Reputable brand
  • thermostatically controlled

Cons

  • Much larger than a tube heater

The Warmax Power 4 by Bio Green is charmingly known as the Bio Green Pal. It Boasts an impressive value for money and stable and intense heat output. The Warmax Power 4 is the smaller brother of the Warmax Power 5 and is designed to provide heating for greenhouses up to 4 m2 (43 sqft).

This units single chimney design with a 4.5 litres tank mean that the Power 4 can be comfortably run for 7 -10 days before you'll need to fill it up, outputting 300w.


This incredible duration is achieved by using an extra-long wick which allows you 40% longer burning time than most other units. The Bio Green Pal can also be used in conjunction with other Warmax units to provide heating for larger greenhouses.

biogreen-wm-p4-warmax-power4

Pros

  • Ten days burn time on one tank
  • Very economical to run
  • Durable design
  • Costs less money to buy than most other electric greenhouse heaters

Cons

This greenhouse heater by Parasene is similar to the previous review. It does not have an electric fan, and temperature control is pretty rudimentary, off or on. This little workhorse will keep your plants frost free during the winter in a greenhouse up 6' x 6'. It is a single chimney design with a slightly larger 5l tank.

Its burn time is not quite as impressive as the Bio Green with just 80hrs on a full tank, but that is still nothing to be sniffed at. What does stand out about this device is its quality.


Its threaded chimneys are brass plated which leads to a premium feeling straight out of the box. The parasense also features a flame extinguishing device to make easy work of turning this unit off when not required.

large-paraffin-super-warm-heat

Pros

  • Very economical to run
  • Brass plated chimney
  • Flam extinguishing device

Cons

  • No thermal cutout
  • No digital thermostat

"Best heater for greenhouse," says one Amazon reviewer. Tootltime has been quietly building a wide array of products over the last few years. What they seem to do very well is produce an affordable product with simple features. This 2ft tube heater is the only electric greenhouse heater you will need. Unlike some of the more feature-rich devices we have reviewed which use an electric fan, this units main selling point is simplicity.

 This is a low wattage unit at just 80w. This is, however, more than enough to heat your greenhouse and maintain a safe temperature for your plants. It is supplied with wall brackets but can also be floor mounted if required. There are no thermostats or thermostatic controls on these heaters, so say goodbye to temperature adjustment; the heat is either on or off. You could supplement this device with a simple time switch or plug if required.

2ft-portable-electric-tubular

This heater is suitable for horizontal mounting only. It is IP55 rated and is built of stainless steel with a white enamel finish. It may look plain, and that is because, well it is. It does the job and nothing more. If nothing else it's an honest little device that may be the most reliable out of all of the greenhouse heaters we reviewed due to its lack of complexity.

Pros

  • Very economical to run
  • No gas or paraffin required
  • Simple design

Cons

  • No thermal cutout
  • No digital thermostat
  • Can only be mounted horizontally

Buying Guide

With such a plethora of options available, it can seem daunting picking the best heater for your greenhouse. The first thing to consider is what temperature you need to maintain. This will vary drastically depending on the crop or plants you are growing. Some plants require a cosy environment to thrive; others are happy if you just keep the frost at bay. Deciding on your required temperature will guide you in the kind of power rating you require.

The second factor is the power rating you go for. It can be tempting to go for a low wattage unit to save money, but this can be a false economy. Depending on your climate, it may cost less money, in the long run, to use a high wattage heater for a short time; as opposed to having a low wattage unit continually on.

You will also have to make a decision on the fuel type you want to use. Electric heaters which come in either a tube form or as an electric fan can get expensive to run. If you have multiple units or you need to constantly raise the temperature for your plants. Paraffin or Propane heaters can be cheaper to run, but if you run out, it's not like you can just replace a fuse or top up your account.

Best Greenhouse Heaters buying guide

Ease of use is probably the final consideration and actually one of the most important for less mobile users. Paraffin and Propane heaters can be efficient and quickly raise the temperature for your plants. This comes at the cost of more labour involved in refilling them and monitoring them closely so as to prevent a fire hazard.


Most electric units come with a built-in thermostatic control which allows you to set the desired temperature range. This means your greenhouse heater will turn on and off automatically without the need for you to worry about whether that fuel will last. An electric unit will also more than likely feature a thermal cutout which will help to prevent a fire hazard if the unit falls off the wall for example and onto something flammable.

Remember that manufacturers often state the absolute maximum there products can achieve in a lab environment. If for example, you have a large greenhouse, do not buy a heater that just about covers the area you need to heat. Save yourself some heartache and spend that extra little bit of money on preventing your prized arrows dying.

FAQ

Q: What type of heater is best for a greenhouse?

A: The best heaters for greenhouses are those that have some type of temperature control. This usually comes in the form of thermostatic control. This will help prevent excess power usage. Electric units should also have overheat protection which means they will cut out before a fire starts. If a paraffin heater falls over, your prized pumpkins may go up in sweet-smelling smoke.

Q: What is the most efficient way to heat a greenhouse?

A: Insulate the walls and floor of your greenhouse as much as possible. Electric heaters for greenhouses are the most efficient system generally. This is because they use a digital thermostat and efficient heating element. Even the best paraffin greenhouse heater will not be able to rival the efficiency of a basic electric unit. An important factor to consider here is what you mean by heat? Are you just looking to prevent frost, or actually maintain a high temperature?

Q: Are greenhouse heaters expensive to run?

A: Most greenhouse heaters operate around 80 to 200 watts. These heaters are often thermostatically controlled and are designed to keep your greenhouse frost free. They are not designed to be used as a large heat source to recreate a tropical climate in the midst of winter. The average electric fan heater uses around 2500w. This means that your average greenhouse heater will cost 2.9 pence per hour (based on average UK kw/h unit price 2020). You could also take into consideration the expense of the environment. If you get your electricity from a green energy provider or use your own solar setup then electric heaters could help lower your carbon emissions.

Q: How to heat a greenhouse without electricity?

A: Depending on the temperature you need to maintain, there is a number of low and high tech alternatives. You can passively insulate your greenhouse with something as simple as bubble wrap if money is a factor. You can also use paraffin heaters or even solar panels to power an electric fan heater if you are worried about an electric bill. It is also possible to use excess humidity to act as a thermal battery; beware, this will make your plants more susceptible to disease.

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About the Author Harry Thompson

Hi, I'm the founding guy of Product Spy. Highly experienced in home and garden appliances through years of online research. I want to help everyone in the UK by streamlining their research when buying a new product. I will be putting the hours in researching to find the best products so you don't have to.