The best pool heaters are far more reliable than the weather. If you’ve ever passed up on a dip because the water is too cold or often feel disappointed by lukewarm pool water, a pool heater is the best solution.
While they don’t come cheap, the result is more than worthwhile, especially if it means more after-work paddles and pool parties. You’ll also be free to choose your ideal water temperature so that you’re always sure what to expect next time you dip your toes into the pool.
Whatever model you may choose, power is paramount. This is measured in British Thermal Units (BTU), and the higher the figure, the quicker you can go from couch to warm pool. Gas pool heaters are the quickest to heat, but they’re also heavier and harder to install. On the other hand, electric pool heaters are lightweight, sustainable, and simpler to set up, but slower to heat up.
Of course, the very best pool heaters don’t just simply heat your pool. Heaters with solar panels will minimize the impact on the environment and reduce your energy usage costs. Then, there are pool heaters that have clever digital temperature controls and indicator lights too. If you want to keep things as simple and budget-friendly as possible, it’s better to stick to a model with both a high BTU measurement and a low weight to keep the installation straightforward - that’s the biggest hurdle when it comes to using a pool heater.
1. Pentair 460737 MasterTemp: Best propane pool heater
Why you can trust Top Ten Reviews Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.
This propane gas pool heater heats up quickly so you won’t have to wait around for hours before taking the plunge. It’s certified for low NOx emission and outperforms industry standards. It has a rotating digital display so it’s easy to view, and user-friendly indicator lights help make it easy to both operate and monitor performance.
The tough, rustproof exterior is designed to withstand all weathers, extending its longevity. The compact design and quiet operation mean you can swim in peace – it hardly makes a sound, so it won’t intrude on your poolside enjoyment.
- Read our Pentair 460737 MasterTemp review (opens in new tab)
2. EcoSmart Smart Pool 18: Best electric pool heater
This differs from other electric pool heaters in so far as it’s an electric tankless heater. Instead of traditional pressure switch activation, the EcoSmart Smart Pool 18 uses flow sensor technology, which increases its reliability and longevity and also reduces the risk of elements burning out.
The EcoSmart Smart Pool 18 electric pool heater has a digital temperature display and dial that lets you set your preferred water temperature in 1-degree increments. It can be used as an alternative to a heat pump or as a booster. It’s compact and lightweight, and it’s energy-efficient – no matter what the ambient temperature.
- Read our EcoSmart Smart Pool 18 review (opens in new tab)
3. Hayward HeatPro HP21404T: Most economical pool heater
This HeatPro electric heat pump is ideal if you’re looking for an electric pool heater that will allow you to extend your pool season. It uses the outside air together with a titanium heat exchanger and profiled fan blade to generate heat for a fraction of the cost of gas pool heaters.
The manufacturers say you could save up to 80% on your pool operating costs. As well as being energy efficient, it’s also easy to install and quiet to run, so you can enjoy your pool and backyard without the intrusion associated with a noisy pool heater.
- Read our Hayward HeatPro HP21404T review (opens in new tab)
4. Hayward H-Series H250FDN: Best natural gas pool heater
The Hayward H-Series H250FDN is an energy efficient, high performance natural gas pool heater. The hydraulic design reduces circulation pump run time. It’s an environmentally friendly option for a gas heater as it produces low NOx emissions.
This heater has a standard cupro nickel heat exchanger and offers ultimate installation flexibility on new or existing equipment pads. The forced draft system moves air through the combustion chamber at a precise flow rate, eliminating the outside weather variables that can affect the performance of a gas pool heater.
- Read our Hayward H-Series H250FDN review (opens in new tab)
5. SmartPool SunHeater S120U: Best solar pool heater
If you’re looking for an eco-friendly, cost-effective way to heat your pool, we think this is it. The universal system is suitable for in-ground or above ground pools, and this solar pool heater could not be easier to install – it’s designed to be placed on your roof, ground or fence, and it works in conjunction with your existing pool pump.
This solar pool heater captures heat from the sun’s rays and can raise the temperature of the water in your pool by 6-10 degrees Fahrenheit, adding weeks to your pool season.
- Read our SmartPool SunHeater S120U review (opens in new tab)
Best pool heaters FAQ
Which type of pool heater should you choose?
Picking the right pool heater for your needs is key, so knowing how to tell apart the different types and how they work is the best place to start. There are three basic types of pool heaters, and they include gas pool heaters, electric pool heaters and solar-powered pool heaters. Heat pumps are another type of pool heater, but they fall under the bracket of an electric pool heater.
The main difference between the three is that they all source their power differently. That has a knock-on effect on elements such as running costs, appropriate climates, and the complexity of the installation process.
Gas pool heaters
Just like your hot water heater at home, a gas pool heater is based upon the process of combustion. That means that it gets its energy from burning natural gas or propane in a combustion chamber. The process heats water, which is fed through the heater, and in turn, warms your pool.
While gas pool heaters are the most powerful option out there, the process requires someone to specially install a gas line and an underground gas pipe. The installation costs can be pretty intimidating, especially if your pool is located far away from the closest gas source. As time passes, the running costs are also likely to be higher because the price of gas is always fluctuating.
As powerhouses, gas pool heaters are the wisest option for heating pools that hold a large volume of water. They’re especially handy if you’re not planning on keeping your pool warm at all times, as they’re the speediest to warm up your pool, and in colder climates since more power is needed to heat up icier pools. The only compromise is gas pool heaters aren’t as friendly to the environment as other solar or electric models.
Solar Pool Heaters
If you’re looking for an environmentally-friendly option for heating your pool, a solar pool heater is high up there. These heaters use natural energy sources: specifically, solar collectors that can pick up the sun’s thermal energy and use it to make your pool warm and toasty.
As well as being eco-friendly and economical, another big perk of solar pool heaters is that they are simple to install. Why? You don’t need to hook the heater up to an energy outlet. The panels do all the hard work for you, and they usually have little to no upkeep costs.
For your solar pool heater to work, you’ll need to position it somewhere with sufficient sunlight, and out of the shade. They work best in hot climates with plenty of sunlight and take a little longer to warm up your pool water than other types of pool heaters.
If you’re a fan of swimming at night, that may mean that you need to buy a diverter, which will add to the overall cost of your pool heater.
Electric Pool Heaters
Electric pool heaters are a popular choice for a reason. First and foremost, they’re incredibly efficient, and as a bonus, it doesn’t matter what time of year it is or the climate you live in. You’ll need to pay more upfront for an electric pool heater, but even though your monthly electricity bill might surge as a result, overall it’s cheaper to run than a gas pool heater.
As for installation, electric heat pumps are more straightforward to install than gas pool heaters because there’s no need to connect them to a gas line. They use ambient temperature to heat your pool water, which isn’t as quick as using a gas energy resource, but they’re a very cost-effective, eco-friendly pick overall.
How does climate affect your pool heater?
Climate is already a huge factor in how often you’ll use your pool, but how does it apply to your heater? Well, some types of pool heater rely heavily on the ambient temperature of the pool, or sunlight in the case of solar models, in order to function. So, there’s a very dependent relationship between some models and climate.
Make sure you factor this into any of your buying decisions and calculations when it comes to pool heaters. If you live in a region with a steady, hot climate, then you’ll be fine to opt for a heater that’s reliant on the ambient temperature. If the climate where you live tends to be a little more temperamental, then you may want to avoid those kinds of models, so you can get more out of your pool, and enjoy it even on days when the sun doesn’t shine.
What size pool heater should you get?
Whether you want a gas, electric or solar pool heater, choosing the correct size heater for your pool is important. Gas and electric heaters are measured in BTU, or British Thermal Units. That’s the amount of energy it takes to raise one pound of water by one degree.
The more you have to raise the temperature by, the more energy you need. It’s worth checking out one of the helpful calculators online to help you calculate the BTU you need in a pool heater. Consult a pool pro for more specific guidance.
What are pool heater thermal units?
As with other household and outdoor products that generate heat, such as gas ranges (opens in new tab), for example, all pool heaters are sized by British Thermal Unit (BTU). As a rough calculation, it takes one BTU to increase the temperature of 1lb of water by one degree Fahrenheit.
The best pool heaters vary from 75,000 BTU up to a whopping, commercial grade 450,000 BTU for really big pools, and obviously the higher the BTU, the more expensive the pool heater.
How long do pool heaters last?
Investing in a pool heater can be a costly business, and you’re probably trying to factor in just how much use you can get from this purchase over the years. The good news is that pool heaters are designed to last between seven to ten years, so you shouldn’t have to fork out on a new one anytime soon. However, the lifespan of your pool heater is of course dependent on how well it’s maintained, as well as how healthy your pool water is. Getting into a good routine with pool cleaning is essential, as well as keeping an eye on chemical levels below the surface.
What’s the best pool heater for you, and are they worth it?
Your ideal pool heater will be dictated by where you live and what heat source you have available, such as gas, an electric heater or a solar pool heater – a good choice if you live in sunnier climes with regular sunshine.
Pool heaters with solar covers are usually cheaper in the long run and can help keep your costs down over the years to come, though the initial outlay is usually a little pricier compared to a standard electric pool heater.
Are pool heaters worth it? In our opinion, yes. Even if you live in a state that’s pretty warm and sunny for most of the year, there will still be days when the water temperature is less than inviting. A good pool heater will ensure your home pool stays open year round, so you can enjoy it much more and get your money’s worth.