Are your greenhouse plants failing to thrive, despite your best efforts? This is a complete guide on picking the right heater for your greenhouse. Below we have a quick table linking you to the individual review type on this page, as well as a link to it on where to buy.
No matter how green-thumbed you are, your plants won’t reach their full potential if they don’t have the light and heat they need. Considering our dreary British weather, this can be quite the problem for hobbyist and professional gardeners alike!
Luckily, there’s a simple solution: greenhouse space heaters. This simple, unassuming appliance can make a huge difference in your gardening efforts by preventing frost damage, improving air circulation, keeping your greenhouse at a steady temperature and ensuring you’re feeling nice and toasty when tending to your plants. Best of all, they shouldn’t cost the earth to run, even with the current cost of living crisis.
In this helpful guide, I’m going to introduce you to the four main types of greenhouse heaters (electric, paraffin, propane and solar) and walk you through the best options I’ve found in each of these categories. Then, I’ll give you some extra tips and tricks on how to insulate your greenhouse so you can get the most out of your greenhouse heaters.
Let’s get to it!
Greenhouse Heater Buying Guide for Beginners
Sometimes, too much choice can be a bad thing, especially if you have no idea where to start. There are so many greenhouse heaters on the market, making it difficult for beginners to find the right product for them.
If you’ve never bought a greenhouse heater before, then you’ve come to the right place. Below, I’ll highlight the four main types of greenhouse heaters and let you know the pros and cons of each one. All you’ll have to do is pick your favourite!
Electric Heating
For most gardeners, choosing an electric space heater is a bit of a no-brainer.
This is because electric heaters have superior heating capabilities and are extremely easy to use. Many electric heaters come with different heating modes, easy-to-use thermostats and timers, making it super simple to set a consistent temperature in your greenhouse and not have to constantly fiddle with the settings. However, please be aware that you can’t leave your greenhouse heater completely unattended – this can be a huge fire risk!
Not only are these settings and built-in thermostats extremely convenient for busy gardeners, but they’re also vital if you need to keep your plants at a particular temperature. You won’t find this level of customisation with other greenhouse heaters, so as long as you have an accessible (and waterproof) power outlet near your greenhouse, you can’t really go wrong with the right electric greenhouse heater in UK weather.
Higher-end greenhouse electric heaters will easily go up to 2kW, which means they can heat larger greenhouses with ease, or make your small greenhouse very toasty indeed! Electric heaters also don’t produce any nasty fumes, which is a definite upgrade from older gas or petrol-based heaters.
However, one thing you’ll need to consider is heat distribution. Your greenhouse heating solution should also ensure that heat is distributed evenly throughout the space, allowing all plants to benefit from the heat and preventing temperature shock in plants exposed to fluctuating temperatures. Greenhouse electric heaters can sometimes be inferior when it comes to heat distribution, but higher-end models often have fans that boost air circulation. Or, as a quick fix, you could place two cheap heaters at either end of your greenhouse for consistent heating.
Another issue you may run into is the overall cost. There are plenty of more affordable electric heaters if you’re feeling the pinch (although they won’t have as many features), but with the current cost of electricity, the running costs could soon start to mount up.
Paraffin Heating
If you’re a gardening traditionalist (or just want a bit of a bargain), a paraffin heater could be the right choice for you. Due to its low cost, longevity and smaller heating capabilities, a paraffin heater could be the best heater for greenhouse heating on a smaller scale.
As the name suggests, paraffin heaters run on paraffin fuel instead of electricity, which means you won’t have to plug this heater into a power outlet or worry about electricity costs. Instead, all you’ll need to do is refuel the tank with paraffin when needed and place the heater on a flat surface with plenty of space around it. Simple!
Another benefit of using a paraffin heater is that it produces carbon dioxide for your plants, giving them the fuel they need. Of course, you’ll need to ensure that your greenhouse is adequately ventilated if you use this type of heater – the fumes certainly aren’t as beneficial (or pleasant to smell) for humans!
Paraffin heaters are perfectly adequate for hobby gardeners with smaller greenhouses, but you may find the higher level of maintenance quite annoying. Unlike an electric heater, a paraffin heater won’t come with a built-in thermostat or easily adjustable settings. Instead, you’ll have to adjust the wick manually to provide the right temperature, and it’s unwise to leave this open flame unattended due to the potential fire risk.
Propane Heating
Next, we have gas heaters or, more specifically, propane heaters. This is another affordable and small greenhouse heater that doesn’t rely on electricity, making it a great option for those worried about electricity costs.
Like paraffin heaters, propane greenhouse heaters simply need to be refuelled when necessary and kept on a level surface. Your propane heater will get very hot throughout the day, so give it a bit of space to prevent accidents.
Again, make sure you ventilate your greenhouse properly if you use this type of gas heater. You can get some nasty fumes from a propane heater, so you shouldn’t be breathing them in! Let the plants have some CO2 and ventilate the rest.
Solar Heating
A new and exciting technology that’s on the rise is the solar greenhouse heater. If you want to reduce your carbon footprint and lower your energy bills too, then a solar heating system could be the perfect solution.
Unfortunately, I haven’t yet found an all-in-one solar-powered portable heater, although this technology could be with us soon. Instead, if you want to use solar power for your greenhouse heater, you’ll probably have to buy a solar panel kit that you can connect to a regular electric greenhouse heater to run it with solar power.
Setting up this heating system might be a bit more difficult at first, but then you can benefit from free and clean energy for your greenhouse. To get started, you’ll need a kit with a photovoltaic (PV) solar panel (usually a monocrystalline one because these are more space-efficient and energy-efficient), a charge controller and a 12V lead acid battery. The battery will store solar power from the solar panel so it can be used at any time, not just when the sun is shining. The charge controller will connect to the battery and solar panel to prevent the components from becoming damaged.
Finally, you’ll need to connect your set-up to an electric heater to create a solar heating solution. To keep things simple, you can use a 12V DC (direct current) electric heater and connect it straight to the solar system. Or, if you have a generic 250W AC (alternating current) heater, you’ll need to connect it to a DC/AC inverter to convert the power to AC for your greenhouse electric heater.
Don’t worry – this sounds more complicated than it actually is! Once you have the initial set-up sorted, your greenhouse solar heater will provide clean and free heat energy for your plants, without any dangerous fumes, open flames or eye-wateringly high running costs. The only downside is that your solar panels won’t create and store energy at night or on very cloudy days. This could be a potential problem during winter months (or even summer months) in the UK!
Tried and Tested: The Best Greenhouse Heaters for UK Gardeners
So, now you know the basics, you’ll be wanting to know more about where you can buy the best electric heaters, paraffin heaters, propane heaters and solar heaters for your greenhouse.
Well, you’re in luck! I’ve compiled a list of the best greenhouse heaters for all situations, including heaters for small greenhouses, large greenhouses, busy gardeners and hobbyists.
Keep reading to discover the best of the best!
Best Electric Greenhouse Heater Heaters
LightHouse 2kW Electric Greenhouse Heater
LightHouse’s 2kW Electric Heater is one of the most popular options on the market, and for good reason! This robust, well-designed space heater is ideal for larger greenhouses at 2kW of power.
One of the best things about this greenhouse electric heater is its customisation options. This heater boasts two power modes (1kW and 2kW), three fan speeds and a min-max temperature dial with six options. Unfortunately, you can’t pick specific temperatures with this heater, which could be an issue if you’re growing plants with very precise greenhouse temperature needs. However, since this heater is thermostatically controlled, it’ll automatically switch on and off according to the current air temperature. This is extremely handy for busy or novice gardeners.
As mentioned above, there are three fan settings: fan only, 1kW fan and 2kW fan. This means that the fan is always running with this device, which will improve air circulation in your greenhouse and allow more heat to spread evenly throughout the space. However, one downside to these fan heaters is that the fan will always be using electricity even when the heating is off, increasing your electricity consumption.
Overall, the LightHouse Electric Heater is a reliable model from a trusted brand, making it a great choice for most gardeners. It’s also not too expensive at a price of £44.50, but remember to factor in your predicted energy costs to this total.
To my knowledge, this heater isn’t IP-rated, which could be an issue if you expect your heater to encounter splashes of water. If you want your greenhouse heater to be waterproof, you’ll need to find one that has a good IP rating.
- Powerful enough for large greenhouses
- Thermostatically controlled
- Robust & reliable
- Always using electricity due to the fan
- High running costs
- No IP rating
Gardeners Corner Hydroponics 2kW Indoor Greenhouse Heater
With a very similar design to the LightHouse heater and a more affordable price tag (£37), you may be tempted by the 2kW heater by gardeners corner. This powerful heater is also well-suited for large greenhouses or a cold winter climate, providing plenty of warmth to help your plants thrive.
The gardeners corner heater is another greenhouse heater with a thermostat and multiple settings, although you still can’t select a precise temperature. The powerful fan will run whenever the heater is plugged in, providing excellent air circulation but also increasing electricity costs.
If you’re looking for a waterproof heater, this model may not be the right one for you. Like the LightHouse 2kW heater, there’s no IP rating in the product specification for this electric greenhouse heater, so you’ll need to be careful with where you place it. Overall, this could be a fantastic dupe for the LightHouse heater, but if you want to go with the more trusted brand, you should perhaps still opt for the first heater on my list.
If you’re looking for a waterproof heater, this model may not be the right one for you. Like the LightHouse 2kW heater, there’s no IP rating in the product specification for this electric greenhouse heater, so you’ll need to be careful with where you place it. Overall, this could be a fantastic dupe for the LightHouse heater, but if you want to go with the more trusted brand, you should perhaps still opt for the first heater on my list.
- Powerful enough for large greenhouses
- Thermostatically controlled
- Affordable
- Always using electricity due to the fan
- High running costs
- No IP rating
Sunhouse (Dimplex Group) SHTTH2 80W Tubular Heater
If you have a small greenhouse, it’ll probably be more cost-effective for you to choose a less powerful electric heater to simply keep the frost at bay. With an 80W tubular heater like this one from Dimplex, you can easily keep the temperature in your greenhouse above freezing with an upfront cost of only £26.99.
In addition, this low-maintenance greenhouse heater is extremely easy to set up, install and adjust. This heater comes with handy mounting brackets for installation, so you can either place it on the walls of your greenhouse or place it between plant containers to provide a concentrated heat source. You could even use multiple tubular heaters around your greenhouse to create various pockets of heat – this will still be a low-cost, low-effort option.
Once your heater is installed, all you need to do is adjust the temperature with the dial at the side. The heater’s built-in thermostat will help you maintain your greenhouse at the desired temperature, keeping your gardening stress-free!
If you’re worried about getting splashes of water on your heaters if they’re between plant containers, don’t be! The Sunhouse 80W Tubular Heater has an IP rating of IPX4, making it splashproof (although it’s definitely not a good idea to submerge this appliance). One potential issue is that the cord is only one metre long, so it’s likely that you’ll need a waterproof extension lead for installation.
- Great for small greenhouses
- Cost-effective
- Easy to install
- IPX4 rating
- Not powerful enough for larger greenhouses
- Cord is only 1 metre long
- Electricity running costs
Ecoheater HHT205 500mm Slimline Eco Heater with Built-in Thermostat (55W)
The is slightly higher-end than the previous entry on this list, but the upgrades you get could be worth it for you.
Again, like the Sunhouse heater, the Ecoheater model is less powerful and uses less energy, making it more environmentally friendly and budget-friendly. Additionally, since it comes with brackets and floor stands, it’s super easy to install your heater wherever you’d like in your greenhouse. Once installed, you can use the built-in thermostat to adjust the temperature of your heating system.
One of the greatest benefits of the Ecoheater Slimline model is that it comes in three different sizes and wattages. There’s a 28W 30cm option, a 55W 50cm option and a 90W 75cm option (at various prices), offering an impressive amount of customisation for all greenhouses.
This greenhouse heater is also fully splashproof with an IP44 rating. The cord is slightly longer than the Sunhouse one at 1.5 metres, but you may still have to buy a waterproof extension lead for easier installation.
- Affordable
- Easy to install
- IP44 rating
- More customisation options
- May still need an extension lead
- Only goes up to 90W
- Electricity running costs
Bio Green Electric Fan Heater 2kW
Are you searching for a premium electric heating system for a large greenhouse? If so, look no further than the Bio Green 2kW Electric Fan Heater!
This powerful fan heater improves air circulation and ventilation at the same time as providing superior heating technology for your growing plants. Like the other fan heaters on this list, the Bio Green heater’s fan runs continuously, which can either be a pro or a con depending on what you’re looking for.
The basic version of this appliance contains a min-max temperature dial and multiple fan settings, allowing you to customise your greenhouse heating to suit your needs. However, if you opt for the premium model, you’ll also receive a highly accurate digital thermostat so you can keep your greenhouse at an exact temperature. This is ideal if you have fussy plants!
Unfortunately, the Bio Green Electric Fan Heater is the most expensive item on the list so far at £129.95 (or £199.95 for this greenhouse heater with a thermostat), but you certainly get what you pay for. This heater is IPX4-rated and designed with robust yet sleek stainless steel, and in addition, its energy efficiency means that your electricity bills won’t be affected as much as you think, even with the fan on all the time.
- Powerful enough for large greenhouses
- Robust design
- Lots of temperature and fan settings
- IPX4 rating
- Expensive
- Electricity running costs
Best Paraffin Greenhouse Heaters
Don’t fancy an electric heater? If you’ve just got a small greenhouse and you’re hoping to keep the frost at bay, a small paraffin heater could be all you need.
CrazyGadget Large Paraffin Super Warm Heater
The CrazyGadget Large Paraffin Heater is an affordable option at £39.99, and best of all, you won’t need to think about electricity costs when running it. Instead, you’ll just need to buy a supply of paraffin, which can last a really long time (depending on how much you use your heater).
This small greenhouse heater comes with a sturdy 5-litre tank that will enable you to burn your heater for up to 80 hours with just one fill. This will give you enough heat to prevent frost damage within a small greenhouse up to a size of 6ft x 6ft.
However, since this is a traditional paraffin heater, you won’t be able to use a thermostat to provide heat within a specific temperature range. Paraffin heaters are adjustable, but you’ll have to manually adjust the wick length to control the flame and its fumes. A wick that’s too long will produce a lot of smoke, which won’t be ideal when you’re trying to work in your greenhouse!
- Affordable
- No electricity running costs
- Will burn for 80 hours on a full tank
- Can’t easily control the temperature
- Produces fumes
Best Gas Greenhouse Heaters
Glow Warm Portable Gas Heater – 4.1KW Indoor Heater with Oxygen Depletion Sensor
If you have a slightly larger greenhouse but still want to use a paraffin heater, then you’re in luck! The Muddy Hands Double Burner Paraffin Heater can provide extra heat while remaining affordable (at £39.99) and cost-efficient.
Just like the CrazyGadget heater, this paraffin heater comes with a 5-litre tank and adjustable wicks, but the key difference is that you get two burners to provide an extra heat boost. This won’t be sufficient for a large greenhouse, but it could be a great option if you have plants that need a bit more heat, or if you feel a bit chilly while doing your gardening.
- Very powerful and ideal for large greenhouses
- No electricity needed
- Portable
- Need to buy butane cylinders
- CO2 fumes (although these can be beneficial for plants)
Bio Green FY 25/GB 2.5KW Frosty Propane Greenhouse Heater
Here we have another entry on the list from Bio Green. This time, Bio Green’s offering is a powerful 2.5kW propane heater with an automatic switch-off feature and no power connection needed.
This propane heater is more expensive than the previous entry at £198.99, but this extra cost is definitely worth it if you want to take advantage of Bio Green’s superior features and design. In particular, you get a precise 0-25°C thermostat, radiant heat distribution from the grid design, stainless steel housing, low-oxygen protection and wall mounting capabilities.
Since this is a propane heater, you’ll have to give it enough space and ventilation for safety reasons. However, the fact that it emits CO2 is also beneficial, as it’ll give your plants the CO2 they crave.
- Powerful 2.5kW heater
- Automatic switch-off safety feature
- Precise thermostat
- Radiant heat distributio
- CO2 fumes (although these can be beneficial for plants)
- Need a propane supply
Best Solar Greenhouse Heaters
Finally, let’s have a look at solar heating for greenhouse plants.
As mentioned before, it’s currently difficult to find a standalone solar-powered greenhouse heater, although this technology is likely to develop quickly in the coming years. In the meantime, you’ll have to set up your own solar heating system with a solar panel kit if you want to heat your greenhouse with solar energy.
ECO-WORTHY 100 Watt 12V Solar Panels Kit
This ECO-WORTHY 100W Solar Panel Kit could help you create the perfect solar heater for greenhouse heating. This kit comes with a solar panel with special tempered glass (helping it perform excellently in harsh weather conditions), a 20A charge controller and a 5m cable. You’ll have to
supply your own 12V battery to store your solar energy.
Setting up a solar heating system sounds tricky, but it’s actually super straightforward with this helpful kit. The solar panel comes with a pre-drilled hole and Z-style brackets to allow easy installation on your greenhouse, and once this is all setup, you can benefit from free and clean solar power for years to come!
- Great value kit including the solar panel, charge controller and cable
- Easy to install
- No running costs
- Need to supply your own battery for energy storage
- Quite expensive
- Won’t produce energy at night
JXKJBGRN Solar Panel Kit
Last but certainly not least, for the final entry on my list of the best greenhouse heaters, let’s look at the 500W JXKJBGRN Solar Panel Kit.
Setting up this greenhouse heating solar panel kit is a doddle. The kit comes with a monocrystalline cell solar panel (which offers 1.3 times more power generation efficiency than polycrystalline technology), a charge controller and four suction cups and two carabiners for easy installation. Again, you’ll need to supply your own battery to complete this greenhouse heater solar set-up.
This brand also offers better customisation options, allowing you to choose between a 10A, 20A and 30A charge controller. In addition, this solar greenhouse heater kit is IP65-rated and can even operate in low-light conditions, meaning you don’t need dry days with direct sunlight to generate solar energy.
At £85-£100 depending on the exact model, this solar heating system is very reasonably priced. If you opt for this kit to set up your solar-powered greenhouse heart, you certainly won’t be disappointed.
- Very reasonably priced for a solar panel kit
- More customisation options with the charge controller
- IP65 rating
- Need to supply your own battery for energy storage
- Won’t produce energy at night
Is Running a Greenhouse Heater Time-Consuming?
Unfortunately, running a heater can be time-consuming. However, this will all depend on the size of your greenhouse, your plants, the type of heater you have and how many heaters you have, so don’t fret – you can make this process as easy as possible!
Paraffin and propane heaters can require more maintenance due to the need to refuel, and paraffin heaters need to have their wicks adjusted manually to control the temperature. With solar greenhouse heaters, the initial set-up can be quite time-consuming as technological limitations mean that you need to install a full solar panel kit with a battery. As a result, all of these heaters can be fairly time-consuming to run.
However, after the initial set-up, solar heaters will run well without too much oversight. Similarly, traditional electric greenhouse heaters require little maintenance, although both of these options are usually more expensive.
Ultimately, you need to balance cost and convenience. Electric heaters can be more expensive to buy and run, but since they’re more powerful and much less time-consuming, they may be worth the investment, especially if you have a larger greenhouse to manage. Hobbyist gardeners with small greenhouses may prefer to cut costs and go for a little paraffin heater that can keep the frost at bay – do what seems best for you!
How Noisy Are Greenhouse Heaters?
It may not be the first thing on your mind, but noise is definitely a factor you should consider when buying a greenhouse heater, particularly if you have neighbours close by.
Generally, hobbyist gardeners with small greenhouses don’t have to worry too much about this, as paraffin heaters tend to not produce much noise at all. On the other hand, gas and electric greenhouse heaters do produce a bit of a humming noise when switched on, which can be amplified if they have a built-in fan for air circulation.
Ultimately, you won’t have to be too concerned about noise if you just have one heater in a small greenhouse, even if this is an electric or gas heater. Problems may arise if you have a large greenhouse with multiple heaters, so if you have close neighbours, make sure you bear this in mind. You don’t want your greenhouse to cause a neighbourhood dispute!
The Best Greenhouse Heater Alternatives
If you’re looking for convenience and effectiveness, you really can’t beat a high-quality electric heater, paraffin heater, propane heater or solar heater for greenhouse heating purposes.
However, if for some reason a greenhouse heater isn’t the right fit for you, there are other ways you can heat your greenhouse and keep your plants happy. A greenhouse that doesn’t need a heater is called a passive solar greenhouse.
Here are some of my favourite alternative greenhouse heating methods for passive solar greenhouses:
- Repair any cracks and gaps around your greenhouse to prevent heat loss.
- Clean all of the windows to let more sunlight in during the day, which will trap heat inside the greenhouse all day and night.
- Insulate your greenhouse with bubble wrap – the air pockets are fantastic for trapping heat in, and the clear material ensures that sunlight can still get through. Make sure you don’t cover the entirety of the greenhouse though because you do need ventilation too!
- Insulate the foundations of your greenhouse with a ‘Swedish Skirt’. Heat loss can also occur through the floor, so insulating the base of your greenhouse can actually make a huge difference. To create ‘Swedish Skirt’ insulation, you just need to dig out some of the soil around your greenhouse to create a slope, and then place rigid foam boards around this slope, extending 4 feet out from the base of your greenhouse. This traps geothermal heat under the structure to keep it warm and toasty.
- Use the quick and easy thermal mass trick with barrels of water. Thermal mass is the capacity of a material to absorb and release heat.
- If you place black containers filled with water around your greenhouse, these items will absorb heat throughout the day and then slowly release this heat at night, helping temperatures stay high enough when there isn’t any sunlight. If you have a small greenhouse, you could grab some 1-litre plastic milk bottles, paint them black, fill them with water and place them around your plants for a quick and easy DIY solution.
- Move your compost heap to the greenhouse. You can put your compost in a large black drum or dig out trenches in the floor for the compost. The chemical breakdowns occurring in the compost will release heat for your plants.
- If specific plants need more heat than others, you can invest in a couple of small heat lamps rather than heating the whole space.
- Cover your greenhouse with a large sheet or sheets at night to trap heat inside. You can also cover your plants with a blanket at night if you’re expecting very cold conditions, but be careful not to crush them!
All of these tips and tricks can help you create an effective passive solar greenhouse, as long as the weather isn’t too cold and frosty. However, it can get pretty cold in the UK at certain times of the year, so you may not always be able to rely on these heating hacks.
To ensure that your plants can thrive in this climate, it’s best to purchase a greenhouse heater that suits your needs. Then, you can use these passive solar heating tips to insulate your greenhouse as well as possible and reduce your reliance on your heater, helping you save an extra bit of cash on running costs
Final Thoughts on Finding the Best Greenhouse Heater
Greenhouses are essential for extending the growing season and allowing UK gardeners to tend to their plants no matter the weather. As long as you have a warm, well-insulated greenhouse, you can garden to your heart’s content all year long.
Although there are many passive solar heating tips to keep your greenhouse naturally warm, sometimes you need a helping hand from greenhouse heaters, especially during the winter months. Electric greenhouse heaters, gas heaters, paraffin heaters and solar greenhouse heaters are all brilliant options, but the best one for you will depend on your personal circumstances and needs.
To discover your perfect heater for greenhouse use, check out my list of recommendations earlier in this article. No matter the size of your greenhouse, your budget or the plants you’re growing, you’ll be able to find a greenhouse heater that ticks all your boxes.
For now, greenhouse electric heaters seem to be dominating the market due to their convenience, efficiency, power and safety, but it will be interesting to see how the solar-powered greenhouse heater takes over in the future. The development of this clean, eco-friendly technology could be revolutionary for the gardening world and all other industries, so let’s see what happens in a few years’ time!
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I’m Chloe, the founder of this site. I was literally born with green fingers and have been into all things gardening since I was a little girl. Gardening is my passion as you can see from the TON of content I’ve published on my site. Thanks for checking out this post but please also take a look around the site to see what else might pique your interest. P.S I am *always* looking for helpful feedback, so if you have something you would like to suggest or just wanna say hi – drop me a message – chloe@getintogardening.co.uk, don’t be shy!
