Pool heaters are great. They help you swim comfortably during the swim season, can extend the swim season by weeks or months, and some types can even allow you to swim all winter.
But there is no one size fits all solution to heating your pool. I’m writing this objective review to lay out the various types of heaters with the pros and cons of each so that you can make the final decision on what is best for your pool.
What is the Purpose of Your Pool Heater?
To heat your pool, right? Unfortunately, the answer is not as simple as that. You have to dig a bit deeper to get the right answers.
Several questions you need to answer before you can pick the correct heater for you:
- How often and during what seasons will you use the heater?
- What is your climate?
- Do you want the ability to swim in the winter or do you just need to increase the water temperature during the swim season?
- Do you have natural gas or propane available?
- Do you have space for solar panels near your pool equipment?
The answer to those questions will help you decide what type of heater works best for you.
Types of Pool Heaters
Pool heaters typically fall into three categories:
1. Gas Heaters powered by either natural gas or propane
2. Heat pumps generally powered by electricity
3. Solar heaters that warm your pool water using the power of the sun
I outline the pros and cons of each type of heater below to help you with your decision.
Natural Gas/Propane Pool Heaters
Gas heaters heat pool water by passing water through a heat exchanger placed under a burner using either natural gas or propane. Your choices for these are limited to your fuel type, typically either a natural gas line to your house or a propane tank on your property.
In general, gas heaters heat very quickly but are also the most costly to operate.
Gas heaters are the only major heater type that involves flames and might be the only option for true wintertime swimming in cold climates.
Pool Gas Heaters: Pros
The biggest pro for a gas heater is the speed at which it will raise your pool temperature. Gas heaters are rated in terms of BTUs, just like your gas grill and the larger the BTUs the quicker it is to get to your desired temperature.
I have a 400k BTU natural gas heater which me the flexibility to heat the spa in about 30 minutes in the winter or decide I want to raise the pool by 5-10 degrees to take advantage of a warm day outside of my normal swim season with just a few hours notice. Other types of heaters require much more planning and do not allow me to have impromptu swimming in the winter.
Relative to the other types of heaters, gas heaters may require the least amount of up-front costs to purchase and install.
Pool Gas Heaters: Cons
The biggest downfall of gas heaters is the cost to operate. Depending on your climate and gas rates, using a gas heater consistently in the winter can cost $500+ per month.
Gas heaters also have emissions from burning natural gas or propane. You can mitigate some of these concerns by purchasing a heater that meets the NOx Emissions Standards, which I highly recommend as they are more efficient and less impactful to the environment. Regardless, you are burning fuel and will always have emissions.
Gas heaters require natural gas or propane, which may not be an option for everyone. Natural gas is typically metered and supplied to your home via pipes, similar to the delivery of city water. Propane is typically stored in a tank on your property which can be unsightly and has to be refilled.
Lastly, gas heaters are typically the shortest-lived of all of the types of heaters. You can help prolong the lifespan by proper maintenance of your water chemistry, especially your pH.
Pool Electric Heat Pumps
Heat pumps work by transferring the heat in your air and putting it into your pool water as it passes through the heat pump. Heat pumps are powered by electricity and are best providing slow and steady heat to maintain your pool at a specific temperature.
Some heat pump models even have a chiller feature that uses the heat pump to chill the pool to keep your pool water refreshing on a hot summer day when the water would typically be too warm to have an enjoyable swim.
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- ECONOMICAL HEATING: Using the surrounding air to heat the pool, HeatPro is...
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Heat pumps may be a good option if you live in a warm or moderate climate and want the ability to swim year-round, or they can be used in colder climates during the swim season extend the season by a few weeks or even months.
Heat Pumps: Pros
Heat pumps are very efficient in warmer climates where the outside air temperatures are above 40 degrees.
As these are so efficient, your costs to use them are typically much lower than gas heaters which allows them to be used over a longer period. It is not uncommon to hear of heat pump users constantly heating their pools during the winter.
Lastly, since they are powered by electricity there is no reliance on having a natural gas line or a propane tank on your property as you would have with a gas heater.
Heat Pumps: Cons
The biggest con of a heat pump is that it works slower than gas heaters. The impromptu wintertime spa evenings that I have with my gas heater would not be possible with a heat pump.
The initial cost is also a con when it comes to heat pumps as they are the most costly type of pool heater to purchase. They typically last longer than gas heaters, so cost may even out over time, but you still have a much larger up-front cost with a heat pump.
Climate can also be a con. Since the heat pump utilizes heat in the air to heat your pool, if your air temperature is below 40 degrees, your heat pump will not operate very efficiently. That rules out many northern areas of the country for effectively using a heat pump for heating your pool.
Solar heaters utilize the power of the sun to heat your pool water. Your pool water is pumped through a series of valves into solar panels mounted on your roof or other location near your pool equipment. These solar panels heat your pool water and it is pumped back into your pool.
One of the many solar heater kits available for your pool:
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Solar Pool Heaters: Pros
Solar heaters have virtually no environmental impact and you harness the power of the sun to heat your pool.
Your operating costs for using your solar heaters are minimal. Usually, the largest operating costs come from having to run your pump longer or at higher RMPs to pump your pool water to the solar panels.
Lastly, it is not uncommon for a solar heating system to last 15 to 20 years and they are typically the longest lasting of all of the pool heaters.
Solar Pool Heaters: Cons
Solar heaters require solar panels which can take up quite a bit of room. It is not uncommon for the solar panels to take up just as much room as the pool itself.
Installing all of those solar panels can also be costly and sometimes cost more than other types of heaters if you need many solar panels.
You also are limited to places that get a lot of sun. Solar heaters work great in places like San Diego where you have sun the vast majority of the days, but it may not be the best choice for someone in a northern climate with less sun.
Lastly, a solar heater is great for adding 10 degrees to your pool water but that is about as much as you are going to get out of them. Do not expect to heat a spa to spa temperatures in the winter by using solar heating.
Other Heating Methods
Solar cover or the more appropriately named solar blanket is a cover that floats on top of your water and reduces heat loss.
- ATTRACTIVE BLUE DESIGN - Sun2Solar solar blankets are made from a film of...
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- JUMP INTO WARMTH - Show friends and family your bravery by jumping in...
- HEAT RETENTION - After everyone has called it a day with wrinkled fingers...
- TRIM TO FIT - Your pool may be uniquely shaped and getting the right fit is...
Solar covers are an excellent way to reduce the amount of heat loss overnight and can be used stand-alone or in conjunction with other heater types.
While they are effective in holding in the temperature, they require you to remove and store the cover for each swim.
Liquid blankets, like this solar pill, helps reduce heat loss similar to a solar blanket.
- Pool Blanket for Up to 12,000 Gallons
- Lasts up to one month
- Easy to use; simply place in skimmer; automatically dispenses
- Reduces heat and chemical loss by preventing water evaporation
- Helps extend your swimming season
The ingredients in these products float on top of the water and are an easy way to keep the temperature of the water up. Typically they do not work as well as a solar cover, but they are easy to add and you do not have to worry about taking the cover on and off of your pool.
Liquid blankets typically last around 30 days until the ingredients are filtered out or degrade.
Just like a solar cover, these can be used stand-alone or in conjunction with a traditional pool heater.
Immersion heaters are a good way to heat a small body of water like an inflatable pool. Simply plug it in and drop it into the water until it reaches the desired temperature.
Make sure you follow the manufacturer’s instructions as some water immersion heaters cannot be in use when you are actively using the spa.
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- Simple Operation: Immerse in water at proper level. Plug into any grounded...
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I love the idea of a picturesque cabin in the mountains with a wood-fired spa to end the day. Unfortunately, reality may not be as good as your pictured.
Wood-fired heaters work similarly to gas heaters in that they use flames with the water pumped through a heating coil that surrounds a wood-burning element.
These may be your only option if you are in an off-grid cabin with a small body of water, but they are typically not efficient enough to be a practical pool heater.
|Recommended Use||Occasional quick heating of pool or spa, the primary option for winter swimming in cooler climates||Slow and steady heating for warm climates||Increase pool temperatures by 5-10 degrees with minimal operating costs|
|Pros||Heating speed||Efficient steady heating in the right climate||• Minimal operating costs|
• Uses the power of the sun
|Cons||• High operating costs|
• Dependent upon the availability of gas in your location
|• High up-front costs|
• Do not work well when the air temperature is below 40 degrees
|• Require sunny climate|
• Require large space for the solar panels
• Limited ability to raise the water temperature
Combining Heating Types
If your budget allows, combining the various types of heaters may be the best way to take advantage of the pros of each heater type.
For example, someone in California may want to use solar heating to extend the swim season and also a heat pump for times when you need to heat your pool beyond the range of a standalone solar heater.
Someone in the Northeast may find the best combination being a gas heater plus a solar cover to retain that warmth overnight.
I hope that this guide helps you with choosing the best way to heat your pool and allow for year-round enjoyment.
Remember, look at the pros and cons for each heater type before you make your decision. Ask neighbors and pool experts in your area to determine what works best for them to heat their pool.
I am passionate about taking care of pools and started over 20 years ago as a young entrepreneur taking care of several neighbor’s pools in the Houston, TX area. Now I live in Prosper, TX, and am known as the Prosper Pool Consultant:
I specialize in solving short-term pool issues with the goal of educating that customer so that they never need my services in the future. It is a unique business model, but I find it very rewarding to see pool owners gain the confidence and tools to manage their pools themselves.