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greenhouse-heater

The UK's bestGreenhouse Heaters2022 Review

What To Look For in a Greenhouse Heaters

The first decision to make when buying a greenhouse heater is the power source. Paraffin, butane and propane heaters are good options if your greenhouse doesn’t have mains power. Paraffin heats up quickly which is great for large spaces, but fuel can be costly. Propane and butane gas are typically more economical, but butane doesn’t reliably burn at temperatures below -2°C.

The best greenhouse heaters are electric; they don’t cause condensation like paraffin or gas and are easy to control. 

Electric fan heaters work well in all sizes of greenhouse. Look for a fan heater with adjustable heat settings and/or a built-in thermostat. These offer more control over the temperature and electricity usage. 

If your aim is simply to keep temperatures above 0°C, consider a low-power electric tubular heater. The purpose of these is to keep frost out. They have around 40 W of power and provide some warmth without hiking up your energy bill.

To keep a standard, small greenhouse (2.4 x 1.8 m) free from frost over winter, a 55 – 80 W heater will be sufficient. However, if you want to maintain a higher temperature, or heat a larger greenhouse, I recommend a more powerful 2 kW heater. 

After comparing some of the best greenhouse heaters, the Bio Green Palma Greenhouse Heater is my top choice. It has a powerful 2 kW output that can effectively heat large greenhouses of up to 5.5 x 2.5 m (18 x 8 ft). It also has an external thermostat that can be positioned right next to plants, providing more accurate temperature readings to the heater. 

Take a look at the reviews below for more information on this greenhouse heater, as well as some excellent alternative options.

What Are The UK's Best Greenhouse Heaters?

IMAGE RECOMMENDED PRODUCTSPRODUCT FEATURES
best-greenhouse-heater Bio Green Palma Greenhouse Heater with Digital Thermostat 2KW
  • Best greenhouse heater
  • Thermostat control
  • Splash proof
best-greenhouse-heater 2kW Electric Greenhouse Heater
  • Best value for money
  • Thermostatic control
  • Comes with a fan
best-greenhouse-heater Bright Spark BS400 Portable Gas Heater
  • Piezo ignition for easy lighting
  • Great budget option
  • Safe and easy to use
best-greenhouse-heater Dimplex ECOT 1ft Tubular Heater with Thermostat
  • Great for small greenhouses
  • Thermostat control
  • Economical to run
best-greenhouse-heater Biogreen WM-P5 Warmax Power5 Paraffin Heater
  • Best paraffin heater
  • Economical to run
  • Traditional design

Read Our Greenhouse Heater Reviews

B00CS52QQG
5055320014966
Best greenhouse heater, Thermostat control, Splash proof,

Bio Green Palma Greenhouse Heater with Digital Thermostat 2KW

best-greenhouse-heater Bio Green Palma Greenhouse Heater with Digital Thermostat 2KW
FEATURES RATING PRICE
FEATURES
  • Best greenhouse heater
  • Thermostat control
  • Splash proof
RATING
100
PRICE
Check Price on Amazon

Bio Green Palma Greenhouse Heater with Digital Thermostat 2KW Review

To keep energy bills down, whilst still keeping temperatures up, this Bio Green Palma Greenhouse Heater is a great option to consider.

Not only is it sufficiently powerful, with a 2 KW output, to keep temperatures comfortable in standard greenhouses, but it also comes with a thermostat that will help control the amount of energy used.

Unlike many other heaters, the Bio Green Palma Heater has an external thermostat that can be positioned right next to your plants. It therefore bases its temperature readings on what the plants feel, not just the temperature immediately next to the heater.

The thermostat can be set to a specific temperatures and is accurate at maintaining the desired heat output. When the thermostat switches off, it switches back on in good time to stop the temperature from dropping too low.

In terms of construction, it’s a robust unit overall, with a stainless-steel body and plastic handle. Plus, it has a water-resistance rating of IPX4, meaning that it is protected from splashing washer (great news for anyone with a tendency to slop the ol’ watering can around!).

To give an idea of this heater’s effectiveness, customers have reported success when using it for a variety of different functions: from overwintering plants and seedlings, to looking after tropical plants such as bananas.

With its power output of 2 kW, it’s one of the best greenhouse heaters for achieving good temperatures over winter. In a standard 2.4 x 1.8 m (8 x 6 ft) greenhouse, the heater can dramatically increase the temperature by several degrees. In larger greenhouses (approx. 5.5 x 2.5 m / 18 x 8 ft) it can still be efficient at warding off frost.

Pros

  • Included external thermostat can be placed remotely where your plants are for greater temperature accuracy
  • Well built and sturdy metal construction, capable of withstanding tough greenhouse conditions
  • Sufficiently powerful to help with overwintering plants and caring for some tropical plants in winter too
  • Good power output for a standard-size greenhouse - 2.4 x 1.8 m (8 x 6 ft)
  • Useful cable length of approx. 2.5 m

Cons

  • Not as effective at raising temperature in larger spaces - can still keep frost at bay
B01DW9ESL2
5060470892258
Best value for money, Thermostatic control , Comes with a fan,

2kW Electric Greenhouse Heater

best-greenhouse-heater 2kW Electric Greenhouse Heater
FEATURES RATING PRICE
FEATURES
  • Best value for money
  • Thermostatic control
  • Comes with a fan
RATING
97
PRICE
Save 16% on Amazon

2kW Electric Greenhouse Heater Review

Effective electric heaters can be expensive, but fortunately this 2kW Electric Greenhouse Heater offers good value for money; it will make a significant increase to temperature in your greenhouse, without making a dramatic decrease to your bank balance.

It has a simple design, with three different heat settings: fan only, 1 kW and 2 kW. There is also a built-in thermostat that helps with controlling energy usage.

Even on the lower 1 kW setting, this heater is capable of providing a reasonable amount of heat to a standard 2.4 x 1.8 m (8 x 6 ft) greenhouse. For example, when it drops below freezing outside, it can keep temperatures at least above 5°C in the greenhouse (and often significantly higher, depending on existing insulation).

When the thermostat switches off, it only shuts down the heating element, leaving the fan running. As a result, this heater’s energy usage will be slightly higher than if the thermostat prompted the whole unit to switch off.

An additional, positive note regarding the thermostat: it’s relatively accurate and doesn’t let temperatures drop too much before turning back on.

In terms of construction, this heater is sturdily made with a solid metal case. On the downside, there is no mention of waterproofing, so it may not be suitable for a very high-humidity environment.

All things considered, if you’re after value for money, this is one of the best greenhouse heaters to go for.

Although it may not have all of the features of the Bio Green Palma Heater – such as an external thermostat – it’s still a robust and effective model. Plus, it’s less expensive.

Pros

  • Robust and sturdy metal construction - capable of withstanding tough greenhouse conditions
  • Easy to install and straightforward to use
  • Versatile - can be used as either a heater or a cooling fan
  • Carry handle makes it easy to move around if needed

Cons

  • The fan runs continuously in the heating modes which means this heater costs more to run than others on the market
  • Not big or powerful enough to heat larger greenhouses - best for small spaces
B004DD1V3U
5060006140198
Piezo ignition for easy lighting, Great budget option, Safe and easy to use,

Bright Spark BS400 Portable Gas Heater

best-greenhouse-heater Bright Spark BS400 Portable Gas Heater
FEATURES RATING PRICE
FEATURES
  • Piezo ignition for easy lighting
  • Great budget option
  • Safe and easy to use
RATING
94
PRICE
Check Price on Amazon

Bright Spark BS400 Portable Gas Heater Review

No mains power in the greenhouse? No problem! The Bright Spark BS400 Portable Gas Heater is a useful little heater that doesn’t rely on having a socket nearby.

As gas heaters go, it’s pretty small and compact, with a foldable handle that makes it easy to take with you as you move between the greenhouse, shed and garage during winter.

It’s worth mentioning straight away that, as there’s no thermostat, this heater it better for supplying shorter bursts of heat, as opposed to being expected to run all night long. It’s fuelled by a butane gas cartridge (not included), and one canister lasts approximately three hours.

When running, the 1.3 kW heat output can kick out some real warmth, even on the low setting. It would be a good heater for keeping you toasty as you work in the greenhouse during the winter months.

Due to its compact design, this heater is extremely versatile. It’s one of the best greenhouse heaters if you want something portable that can be used in a lot of different contexts. Seeing as it doesn’t rely on a mains power supply, it can also be used when camping or sitting out on the patio.

If you don’t have a way to run an electric heater in your greenhouse, this is a good option to consider. It can take off the chill, but won’t raise temperatures to a large degree.

Running time is finite, but the gas canisters are easy to remove and replace. The only thing to bear in mind is that you’ll need to keep buying more which is an expense that can add up over time.

Pros

  • Can be used in greenhouses where there is no mains power available
  • Takes the chill off small spaces in the winter months
  • Gas canisters are easy to remove and replace
  • Produces an impressive amount of heat for such a small unit
  • Lightweight and compact - easy to carry around whilst working in different outbuildings during winter

Cons

  • No thermostatic control so needs to be switched on and off manually
  • Relatively high gas consumption - one canister every three hours - can mean that heating costs add up
  • Better for supplying short bursts of heat rather than maintaining a steady, elevated temperature
B00NT0X8K2
5054814088223,5011139049667,5054242206053,0791963234198,8944467905190
Great for small greenhouses, Thermostat control, Economical to run,

Dimplex ECOT 1ft Tubular Heater with Thermostat

best-greenhouse-heater Dimplex ECOT 1ft Tubular Heater with Thermostat
FEATURES RATING PRICE
FEATURES
  • Great for small greenhouses
  • Thermostat control
  • Economical to run
RATING
91
PRICE
On sale at Amazon

Dimplex ECOT 1ft Tubular Heater with Thermostat Review

Sometimes, keeping the greenhouse free of frost is all you need – and there’s no need to spend loads to achieve it. This Dimplex ECOT 1 ft Tubular Heater is cost effective, both to buy and to run, and will stop plants from withering under the icy claws of Jack Frost.

Running at just 40 W, it might not seem like much, but this heater creates enough heat to keep temperatures above freezing in small greenhouses. Plus, such low wattage means that it’s relatively cheap to run and can be left on for extended periods.

There’s also a built-in thermostat, to further control energy consumption. There are no temperatures marked, but instead a scale ranging from ‘min’ to ‘max’. There is no specific frost setting, so some trial and error may be required to find the right temperature.

As a tubular heater, it’s easily mounted onto wall brackets; the benefit of this is that it can be kept out the way, allowing you to benefit from more floor space in your greenhouse. The mounting brackets are included.

It’s IPX4 rated, making it splash-proof and safe for use in greenhouse conditions. As a result, there should be no complaints from the heater if you are slightly over zealous with your watering-can usage.

Whilst this is overall a very useful heater, and one of the best greenhouse heaters for keeping frost at bay, it does have one primary shortcoming. The power cable is only 1.5 m long, which can be a little short for some greenhouses, particularly if the socket is awkwardly positioned – just something to be aware of.

Pros

  • Extremely cost effective to run - potentially costing just a few pounds per month
  • Does a great job at protecting plants from frost and taking the chill off freezing days
  • Thermostatic control means it saves power by turning off toe maintain the desired temperature
  • Comes with mounting brackets that make it very easy to install

Cons

  • Needs to be wall mounted which can be difficult in some greenhouses
  • No specific temperature markings on the thermostat dial, only 'min' and 'max'
  • Won't significantly raise temperature by several degrees - simply takes the edge off freezing greenhouses
  • 1.5 m cable may not be long enough to reach power socket depending on greenhouse layout
B002UKPX5U
5055320002000
Best paraffin heater, Economical to run, Traditional design,

Biogreen WM-P5 Warmax Power5 Paraffin Heater

best-greenhouse-heater Biogreen WM-P5 Warmax Power5 Paraffin Heater
FEATURES RATING PRICE
FEATURES
  • Best paraffin heater
  • Economical to run
  • Traditional design
RATING
88
PRICE
Check Price on Amazon

Biogreen WM-P5 Warmax Power5 Paraffin Heater Review

Paraffin greenhouse heaters like the Bio Green Warmax Power 5 Heater have been popular amongst gardeners for a long time. It’s easy to see why, given that this model is efficient, easy to use and practical.

First of all, there’s no requirement to have a mains power socket nearby, making it viable for all kinds of greenhouses. Secondly, the heat output can be adjusted depending on how many wicks are lit, and it can burn for several days.

The paraffin tank has a capacity of 4.5 L and requires a funnel (not included) to help with the fuelling process. As mentioned, this is enough paraffin to keep the heater going for approximately three days.

With both burners lit, this heater has the power to keep temperatures above freezing in a 3 x 2.4 m (10 x 8 ft) greenhouse. It’s also suitable for smaller greenhouses as it’s possible to only light one of the four 30 cm wicks. This means that less fuel can be used the majority of the time, but if a boost is needed, the other wicks can be lit.

In terms of safety, the open flame is covered by the flues, so there’s no naked flame to worry about. However, it’s worth noting that the strength of the metal flues could be higher, and some care needs to be taken not to bend them when removing and replacing them.

Although paraffin can be expensive to buy, this heater is at least economical in its usage. It’s therefore one of the best greenhouse heaters to buy if you want something that’s gas powered but not too costly to run for longer periods of time.

Pros

  • Does a good job protecting small to medium greenhouses from frost
  • Versatile warmth levels with 4 wicks that can be lit individually or together
  • Open flame is covered by flues to make running the heater safer than an uncovered flame
  • Heater can burn for several days on one tank of fuel

Cons

  • Only effective in small greenhouses, can’t be used to heat large spaces
  • Brass plug to the paraffin reservoir can be difficult to unscrew
  • The metal flues can bend so care needs to be taken when removing and replacing them
  • Paraffin can be costly to buy - although at least this heater is economical with its usage

How to Choose the Best Greenhouse Heater

Ah, greenhouses! Also known as ‘our best bet for keeping plants alive’ during winter here in the UK.

Using a greenhouse heater will not only help keep your plants healthy, it will also help protect the structure of the greenhouse. If there is too much moisture hanging around during winter, mildew and mould can grow. This might affect the greenhouse itself just as much as the plants.

Greenhouse heaters can help maintain a reasonable temperature in the greenhouse and keep air circulating. Some are best used for keeping temperatures just above freezing, whilst others can increase the temperature by several degrees.

Choosing the best greenhouse heater will depend on a couple of things, including what you want to use it for and how much money you’re willing to spend (both on the initial purchase, and running the heater). The following information will give you a better idea of what to look out for (and what to avoid as well!).

There are a few different types of greenhouse heater available, and different styles can be more (or less) useful, depending on the situation. Here’s a run down of the most common greenhouse heaters:

Paraffin Heaters

Paraffin heaters for greenhouses have been around for years. Even now, they haven’t veered much from their original designs. They have a tank that is filled with paraffin, and a wick that soaks in the paraffin and slowly burns down. Paraffin heaters can have more than one wick, and the ‘power’ output of the heater is usually determined by how many wicks are lit.

The benefits of using a paraffin heater are that they can be used anywhere (with no need for a power socket) and they can run for a long time without needing refuelling. Heaters with a tank of 4 L+ will be able to burn for several days.

Whilst this can make paraffin heaters seem an economical option, buying paraffin gas in the first place can add up. Paraffin heaters will likely be more expensive to run than an economical electric heater; nevertheless, if you don’t have anywhere to plug in an electric heater, they can be a viable option. Their wicks will also need replacing once they burn down.

You will need to consider creating an ‘exhaust hole’ in your greenhouse if you choose to use an unvented gas heater.

Gas Canister Heaters (eg. Butane)

Much like paraffin heaters, heaters which are fuelled by gas canisters (commonly filled with butane) can be used wherever necessary. They don’t rely on the presence of a nearby plug socket.
Due to the small size of greenhouse heaters in general, canister heaters will likely only be able to carry a small gas canister. As a result, they do not tend to burn for as long as paraffin heaters.

Butane heaters are useful for supplying heat for a few hours, but it is unlikely that a small gas canister will last the whole night.

Electric Fan Heaters

The cost of running an electric fan heater can add up; however, they can also be some of the most effective heaters for dramatically increasing the temperatures inside a greenhouse (depending on their wattage).

To run an electric fan heater, you’ll need a waterproof power socket sufficiently close to where you wish to place the heater. This can pose a problem in some greenhouses.

Fan heaters may come with a choice of heat settings, and/or a built-in thermostat. Both of these can be useful when it comes to trying to curb energy consumption.

An effective 2 kW fan heater has the power to keep the greenhouse temperature above 5°C even when it’s freezing outside. However, as you can see below (in the section titled ‘Energy Efficiency and Running Costs’), constantly running a heater on this power could get expensive, fast.

Low-Power Electric Tubular Heaters

These can be very effective at preventing frost inside a greenhouse; however, they’re not suitable for significantly raising the temperature more than that. Electric tubular heaters can require as little as 40 W to run (or less). Therefore, they can be left on consistently without there being too much danger of racking up huge electricity bills.

They’re a good option for keeping temperatures just above 0°C, but you can’t expect much more from them – especially if it’s very cold out.

Most greenhouse heaters are designed to be as energy-efficient as possible. By nature, electric heaters are known to be extremely energy efficient; however, this doesn’t necessarily mean they’re the cheapest to run.

Gas heating in a greenhouse it generally considered to be a relatively cheap option. Using a gas heater can keep costs down because you know exactly how much money you have spent on fuel before it even starts heating. Gas heaters are like one of those pay-as-you-go electricity meters – you’ll be aware of all running costs up front.

As mentioned, electric heaters are energy efficient. They don’t produce fumes, as gas heaters do, and therefore don’t require any ventilation in the greenhouse which leads to heat escaping. However, it can be very costly to leave an electric heater on for days on end (depending on the type of heater you choose).

The cost of running an electric heater depends on the kW setting of the heater.

If you pay your electricity company 19p per kWh  (which is roughly the UK average, but you should check your specific rate) then it will cost 19p (£0.19) to run a 1 kW heater for an hour. Therefore, it will cost approximately 57p to run a 3 kW heater for an hour. And if you run a 3 kW heater for 8 hours… well, you’re looking at a running cost of £4.56 for that time period.

If you only know the wattage of a machine, and not the number of kilowatts, you need to divide the number of watts by 1000 to find out how many kilowatts it uses. A 2000 W machine will use 2 kW.

With all this information in mind, you should look carefully at the power of the heater you’re thinking to buy.

Look for a heater with adjustable settings, and work out how long you can realistically afford to keep it running for (and if that will actually serve your desired purpose or not).

Whilst buying a heater can help improve temperatures, if the greenhouse isn’t well insulated a lot of that heat will escape.

Sealing any cracks or holes will be crucial for keeping temperatures up over winter. But that’s not all you can do – a lot of gardeners put up greenhouse insulation in order to keep warm air inside the greenhouse (and insulation can also help seal any leftover draughts).

Bear in mind, with unvented gas heaters you will need to leave some sort of ventilation. Therefore, some heat will escape.

One of the most popular types of greenhouse insulation is bubble wrap. Whilst standard bubble wrap can be used, and be somewhat effective, it’s better to buy a product that has been specifically designed for greenhouse insulation. Look out for large bubbles and UV-resistant materials. This will help enough light enter the greenhouse and ensure that the bubble wrap doesn’t degrade.

You can also use horticultural fleece to insulate the greenhouse. Fleece can help reduce condensation as it is more breathable. However, it blocks more light than bubble wrap.

Greenhouse Heater FAQs

You should consider purchasing a low-power tubular heater. These are inexpensive to buy and also cost very little to run. They are usually around 40 W. Make sure the heater has a thermostat to help with controlling energy usage.

It’s also important to insulate the greenhouse in order to keep the frost away, as well as seal up any cracks which may allow cold air to creep in.

This will depend on the size of your greenhouse, your access to mains electricity and the specific conditions your plants require.

Electric fan heaters are some of the most efficient at noticeably increasing temperatures. However, they are expensive to run for long periods of time and some plants may not require that much heat. Low-energy tubular heaters can help if you’re looking to just keep your greenhouse above freezing. Both of these options require access to mains electricity, which you may not have.

If you don’t have access to mains electricity, a gas-powered heater will be the way to go.

There are a lot of tactics for keeping your greenhouse warm over winter, with or without using electricity.

A greenhouse heater is a sure-fire way to keep your greenhouse warm and at a steady temperature. You could also move your composting facilities into the greenhouse – composting materials create heat. Wrapping up a small greenhouse with insulating material such as bubble wrap is another option, or you could section off part of the greenhouse with plastic to keep that smaller section warmer and more insulated.

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