Last updated on August 2nd, 2023
Our site is reader supported, this means we may earn a small commission from Amazon and other affiliates when you buy through links on our site.
I’ve had several garden swimming pools over the years, from a smaller 6ft inflatable single ring pool from Intex to a larger 12ft framed pool from Bestway and a smaller 8ft framed pool. I’ve talked about my experiences with garden swimming pools here. However, one investment I wished I’d made sooner was getting a decent pool heater. Once I did, the kids couldn’t wait to get in.
In my review, I will discuss my thoughts on which are the best pool heaters; this includes both electric pool heaters and solar powered pool heaters.
A couple of things to keep in mind, with all pool heaters, you need a pool filter pump like my Intex Krystal Clear Swimming Pool Filter Pump pictured above to pump the water through the pool heater.
With all these pool heaters, you connect them between the pool filter pump (the outlet pipe) and the return hose back into the pool. If you already have a pool pump that has a flow rate of over 2000 L/Hr, it should be fine. I’ve talked about choosing a pool filter pump in this guide which might be useful. The faster the flow rate, the more effective the pool heater will be as its transfers water through the heater more quickly and back into the pool. The larger the pool volume, the longer it takes to heat up!
You can also connect a pool skimmer which I have discussed here and shown in the picture above but you need a decent flow rate of at least 3000L/H to run the skimmer and heater together because of the pressure needed.
Before I get into my detailed reviews below, I want to quickly talk about two of my favourite pool heaters. If you want to learn more about choosing a pool heater, I also have a buyer’s guide that is worth reading further down.
I’ve tested several heaters for above ground garden pools which I recommend for most pools between 6ft and 12ft, maybe 15ft but more on this below.
I currently have this Intex 2.2 KW Electric Above Ground Pool Heater. This is my favourite heater. It’s reliable, simple to use and has increased the water temperature to a comfortable 28 degrees when the outside air temperature was only around 12 degrees, its even been into the 30s before now too. What I like about this electric heater is that their easy to use and compatible with most garden swimming pools. This includes both Intex and Bestway pools, as they both use the standard push fittings with little plastic clamps.
I currently use this pool heater with my 8ft frame pool with my Intex Krystal Clear Swimming Pool Filter Pump. Both the pump and heater are rated for pools up to 15ft. However, I think a 12ft pool is realistically the limit. If you have a 15ft pool, I would upgrade the pump to get a better flow rate. Overall, I think this is a great electric pool heater for most pools under 12ft.
More recently (last two years), I started testing this Intex Eco-Friendly Solar Heating Mat shown above attached to my Intex inflatable ring pool. I’ve been so impressed with it and wish I had invested in it years ago. When I first used it, I couldn’t believe how effective this solar heater was, especially considering it has zero running costs. It’s super easy to install, and the pool gets to a toasty 24-26 degrees on a nice sunny day after about 5-6 hours of sun. Thats the same as my electric heater!
Here are a couple of things to keep in mind. I can only use my solar pool heater when the sun is shining, and I live in the UK not known for getting lots of sun. If it’s cloudy, it’s a waste of time and does nothing. It would be best if you ideally had an electric heater and this solar heater. I usually use my solar heater if I have a lovely weekend forecasted with clear skies. If it is warm and cloudy, I use my electric heater.
Something else I always do for safety is turn the heater and pump off when the kids are in the pool. I usually switch the electric pool heater on around 6-12 hours before it will be used.
4 Best Pool Heaters
1. Intex 2.2 KW Electric Pool Heater
Buy on Amazon.co.uk
Over the years, I’ve had a couple of electric pool heaters. Personally, I prefer this Intex 2.2 KW Electric Pool Heater over the Bestway model, just my personal preference after having owned both and find this Intex 2.2 KW Pool Heater easier to use with no fancy LED screen that’s hard to read when the sun glares against the screen. Just a simple on/off button. I’ve had this Intex for a couple of years now and it’s been very reliable, easy to use and does a great job at heating the pool to a nice 30 degrees plus.
A couple of things to note, don’t expect these heaters to work wonders and give you a warm pool within a couple of hours; this isn’t how they work. Generally, they can increase the temperature by around 0.5-1 degree every hour, but this heavily depends on the water temperature to start with. To give you an idea, I usually have the heater on 12-24 hours before I know the kids will use the pool, usually at weekends or summer holidays.
I have used this pool heater on an 8ft rectangular framed pool, and it took the water temperature from a chilly 18 degrees to a comfortable 28 degrees in around 10 hours. Another time it was 10 degrees, and took around 12 hours to reach 22 degrees. The point here is that it depends on the outside temperature. Also, get yourself a pool cover to help retain the heat, this helps alot and is definitely money well spent.
I have also used a solar heat mat which I have also reviewed below which gets my pool to around 24-26 degrees. The problem is it only works if it’s sunny! If it’s cloudy, it’s a waste of time. This is where a good electric heater comes in. If it’s cloudy in the morning but sunny in the afternoon, I can use the electric heater instead. Don’t get me wrong, the solar heater is great but only on warm sunny days with blue skies.
Now, what about the power cord, they are frustratingly short. This is one of the issues with all electric pool heaters, they all have short power cables. Ideally, you need an outside socket. I actually installed 2 Gang IP66 rated Waterproof Outdoor Extension Lead Socket and plugged it into my garage socket. This has worked great for me, you could also have a professional install an outside plug socket.
Something else I forget to mention is that you need to connect this heater with a pool filter pump. I currently using this with an Intex Krystal Clear Swimming Pool Filter Pump which has a flow rate of 2006 litres per hour and it works perfectly fine. This heater needs to be used with a pump with a flow rate between 1893 – 9464 litres/hour. It’s worth noting the faster flow rate will help speed up how quickly the water heats up.
It’s designed to work with any pool that has up to a 17,033 litre capacity and is 2.4m to 3.6m in diameter so basically most 8 to 12ft pools. I’ve used this pool on my other Intex 6ft round pool and it also works great but I’ve only used it on a framed pool up to 8ft personally.
When using any electric pool heater, remember that you’re heating a great deal of water through a relatively small appliance. It will take quite a while (hours or even a day or so) for the entire pool of water to reach the temperature you want. And that adds quite a cost to your electric bill.
Pros
- Easy to use electric pool heater for pool 2.44m to 3.66m (8ft to 12ft) in diameter.
- Connections will fit most Intex and Bestway pools which have inlet and outlet for a filter pump.
- Pool capacity to be a maximum of 17,033L.
- Flow rate is 1,893L/hr to 9,464L/hr.
- Connects in line with your pool filter pump.
My recommendation
If you have an Intex or even a Bestway above-ground pool then this is a great electric pool heater to consider. I find that it’s not cheap to run but then nothing is cheap at the moment with energy prices. To give you an idea, it’s costing me around 90p an hour to run according to my smart meter, however, this is well worth spending and the pool is used more now too.
Overall, I like it because it’s easy to use, seems fairly efficient and it’s been very reliable. Remember these heaters are designed to be used 12-24 hours prior to actually needing the pool.
2. Intex Eco-Friendly Solar Heating Mat for Swimming Pools
Buy on Amazon.co.uk
I delayed getting solar heat mats until 3 years ago and I wish I had tried them years ago when my elder daughter was younger. I could have saved so much money over the years. First, don’t expect miracles, these work great when it is sunny and it does warm the water to a similar temperature as my electric heater. I had the water go from around 14 degrees in the morning to around 26 degrees recently in the afternoon on most sunny days. I do have a south-facing garden so I do get sun on the back all day which obviously helps.
I recommend using these solar heat mats when sunny and you can take advantage of free solar heat and have an electric heater like the Intex 2.2 KW Pool Heater to use when the weather is not on your side. Like the electric pool heaters, you have to have them connected to a filter pump to pump the water through the heat mat and then back into the pool. The bigger the pump, the more efficient it will be. I use them with the Intex Krystal Clear Swimming Pool Filter Pump & Cartridge but if you have a pool larger or more than 2 mats, I would probably upgrade the pump to either the Bestway Flowclear Sand Filter System with ChemConnect (Brilliant filter pump) or the Intex 634T Krystal Clear Filter Pump which has a flow rate of 2500 L/hour.
How they work is the water from the pool flows through the pump filter and then out through the solar mats, which are heated by solar power (the sun heating up the black mat). The water is heated as it goes through the mat and is then returned, warmed, to the pool.
This Intex solar heating mat works well with most filter pumps that have a filter flow rate of up to 9,465L/hr or more importantly, above 2000L/hr. Pools with a capacity of up to 30,280L can be heated with this solar mat but for large pools, you can join several mats together. Just remember the more heat mats you have, the more power you need so the larger pump you will also need.
Please be aware that the solar mats’ effectiveness depends on the amount of sunlight they receive. If it is not sunny, they will not be effective which is why I have both electric and solar heat mats to swop between as and when needed.
Pros
- Solar heating mat for increasing the temperature of your pool water for free.
- On sunny days can heat the pool to a respectable 26 degrees.
- Can joint multi heat maps together for large pools.
- Use in-line with a filter pump of less than 9,463L/hr flow rate.
- Attachment point for 32mm hoses and adapters for 38mm hoses.
Cons
- Effectiveness is dependent on the weather, no sun, no heat.
My recommendation
This Intex Eco-Friendly Solar Heating Mat is the pool heater I wished I had invested in sooner. As I’ve already mentioned, when it is sunny they do a great job and I have used mine alot this year. However, unless you only get the pool out when it’s sunny and blue skies, you really need an electric pool heater for when the sun is refusing to make an appearance. After all, the UK is not known for its sunshine.
There are a few of these solar pool heaters around. However, I prefer this Intex model over the very similar Bestway alternative because this Intex Eco-Friendly Solar Heating Mat comes with pipes that push on (not screw), which most pools have. The Bestway solar mat has a screw-on fittings, so you might need to buy attachments to make it compatible with your pool unless it has screw-on fitting.
Also, I prefer to use the Intex solar mat as I can quickly switch between the heat mat and the electric heater, both have push-on fitting with small plastic clamps and are super easy to change. Overall, a great investment and a free way to heat your pool when it’s sunny. For the price, these are well worth getting even if it’s only to supplement an electric heater when it’s sunny.
3. Bestway FlowClear Pool Heater
Buy on Amazon.co.uk
This is a good alternative to my Intex 2.2 KW Electric Pool Heater, it is very similar in performance. I just prefer the Intex version but this is just as good, it just takes a little more effort to get it switched on and it’s not easy to see the LCD screen or the power light if the sun is shining on it. Once you’ve plugged it in, it beeps to indicate it is ready but the heater is still off. You have to press and hold the button for 2 seconds before it will start heating. Just something to note!
Like the Intex heater, it’s designed for above ground pools with a capacity of between 1,520L and 17,035L. This covers most at-home pools, so yours probably fits in this range. To give you an idea, it’s supposed to be fine with pools up top 15ft; personally, I think it’s more like 12ft. I know this because my brother has a larger 15ft Intex pool, and he tried this heater first, it did warm the pool, but it wasn’t great. I think the water volume is just too much to expect this little heater to warm it. However, under 12ft and it’s a good option and will give you a nice bath like warm water. Basiclly for smaller pools, all these plug-in electric heaters are great, for larger pools, not so much.
You can use either cartridge filter pumps or sand filter pumps with this pool heater, I’ve reviewed both on this review. I highly advise you to double check the flow rate of your filter pump. This Bestway pool heater can deal with a maximum filter pump flow rate of 3,785L/hr and many filter pumps have flow rates that are more than this. Your filter pump may put out too strong a water flow for the pool heater to deal with.
This Bestway model has automatic temperature regulation too. It heats the water up to 40C (if you are lucky) before it shuts off.
As with any electric pool heater, the length of time taken to heat the pool water depends on the starting temperature of the water and the surrounding air temperature. It could take a few hours or 24 hours. Don’t forget, using a solar cover on your pool when heating it up helps to conserve the warmth the heater generates.
Pros
- Electric water heater for above ground pools.
- Maximum heater output is 40?C.
- For pools with a capacity between 1,520L and 17,035L.
- For filter pumps with flow rates up to 3,785L/hr.
- Automatic temperature regulation.
- Includes two 32mm hoses and attachments.
My recommendation
Overall, if you have a pool between 8ft and 12ft, this is a great option for heating your pool. I’m a little biased as I love my Intex pool heater but they are very similar. Both are great pool heaters, personally, I have the Intex version but this Bestway heater is honestly just as good.
If you have a Bestway pool and pump already then maybe go with the Bestway heater, if you have an index pool and pump, maybe go with he Intex pool heater.
4. Bestway Flowclear Solar Pool Heater
Buy on Amazon.co.uk
Finally, I have another solar powered heater to consider, this Bestway Flowclear Solar Pool Heater which is very similar to the Intex solar model reviewed earlier.
This Bestway Solar Panel Pool Heater is ideal for pools up to 30,280L capacity, the same size as the Intex one. And it also handles cartridge filter pumps of the same flow rate, 9,463L/hr, plus sand filter pumps of up to 8,327L/hr flow rate can also be used.
Just remember that you need the sun for this solar pool heater to work just like any other solar heater. Don’t forget to put a solar cover on the pool when it’s not in use to conserve whatever heat there is already in the water.
Pros
- Solar heating mat for your above ground pool.
- Increases pool temperatures by 3?C to 5?C.
- Weather resistant.
- For above ground pools of less than 30.280L capacity.
- Use in-line with a cartridge filter pump of less than 9,463L/hr flow rate.
- Use in-line with a sand filter pump up to 8,327L/hr.
- Attachment point for 32mm hoses and adapters for 38mm hoses.
- Dimensions: unfilled: 1.10m x 1.7m.
Cons
- Effectiveness dependent on the weather.
My recommendation
This Bestway Flowclear Solar Pool Heater is another sun-driven pool water heater. Remember that you still need a filter pump to circulate the water through the solar heater. And putting a solar cover on the top of the pool keeps the heat in.
Buyer’s Guide
This Buyer’s Guide for above ground pool heaters briefly explains how these pool heaters work. It goes on to define the two numbers you need to know in making your best purchase decision.
How does a pool heater work?
In general
Here’s how you connect your heater into your pool system. The filter pump takes water from the pool and pushes it through the heater and back out to the pool.
Pool -> Filter pump -> Heater -> Pool
Electric pool heaters
Electric pool heaters don’t actually generate heat to warm the water. Here’s how they heat the water:
- A fan pulls outside (warm) air into the heater over the evaporator coil. This causes the liquid refrigerant inside to heat up and turn into a gas.
- This refrigerant gas enters a compressor which increases the pressure and temperature of the gas.
- The gas is now hot and goes into the condenser heat exchanger. The heat transfers into the cold pool water.
- The hot gas has now lost some heat and cools off. it changes back to a liquid state and enters the thermal expansion valve.
- In the thermal expansion valve, the gas expands, cools off further as well as loses pressure and starts the cycle again.
- The warmed water goes into the pool.
Note: the higher the outside air temperature and humidity, the less energy the electric pool heaters take to heat the pool.
Solar pool heaters
The solar pool heaters in this review are basically blankets made of “bubbles”. The bubbles use the sun’s rays to trap heat in the blanket and this heats the water that passes through the blanket. The filter pump pushes water through the blanket (where it’s warmed) and back into the pool.
Numbers to (double) check
Size of your pool
Most pool heaters give the capacity of the pools they can work with, rather than the pool’s dimensions. Capacity is the volume of water the pool holds and is given in litres (L) or sometimes gallons (g). You’re usually given a range of capacity, so check that the number of litres of water that your pool holds is in that range.
If your pool is too big for the size of your pool heater, the water will never be warm enough.
Flow rate of your filter pump
Your filter pump takes the water from your pool and pushes it through the pool heater, after filtering it. The pool heater can handle a certain rate of water flow, usually given as a range or a maximum number. Flow rate is usually given as litres per hour (L/hr).
It’s important to make sure that the flow rate of your filter pump is within the range that the pool heater can handle. If the flow rate is too big, then the water doesn’t spend enough time in the heater and won’t warm up enough. If the flow rate is too small, then the filter pump isn’t strong enough to circulate the water and only the top part of the pool water becomes warm.
And a warning
DO NOT use the pool heater without the filter pump running. The heater needs water inside it to work and it’s the filter pump that pushes the water there. When turning off your pool system, turn off the heater first and then the filter pump.
Final conclusion
You do have to pay in additional costs on your electric bill for the luxury of warm water in your above ground pool. But given that, the choice comes down to an electric pool heater for significant jumps in water temperature or a solar heating mat for smaller temperature rises. Your choice could depend on the climate you live in (cooler and overcast vs warmer and sunny), the size of your pool, or how often you plan to swim.
In all cases, consider using a solar cover to preserve the warmth your pool heater generates.
Last update on 2024-04-09 / Affiliate links / Images from Amazon Product Advertising API
