How To Choose A Pool Heater: The Compete Buyers Guide

Swimming pool heaters have become a popular trend in recent years due to the fact they can extend the swimming season by months at the very least. Depending on the climate, they can also be used to extend the season year-round or to protect the plumbing of the pool during the winter months. In this article, we will go over a complete buyer’s guide to choosing each of the different kinds of pool heaters.

Typically, picking the right pool heater for an individual’s pool falls back on what is wanted, needed, and what is available for that particular size and type of pool. Read on to avoid selecting an inappropriate heater for your swimming pool so that it lives up to and exceeds your expectations.

Picking the Right Pool Heater

Many factors come into play when selecting the appropriate heater for an individual pool. The biggest issue behind negative reviews on a pool heater is that the heater itself did not live up to the expectations of the purchaser, and typically, this is due to selecting an inappropriate heater for that particular pool.

See below to find the factors that need to be considered when selecting a pool heater.

Expectations and Needs

The first factor to finding the right pool heater for your pool is your expectations and needs. These are some questions you might want to ask yourself to find them:

  • Why do you want a heater in the first place?
  • Why might you need a heater?
  • What do you want the heater to be able to do?

Now, let’s move on to the next factor to choosing the right pool heater.

Pool Type

Another thing you should consider when choosing the right pool heater is the type of pool you have. There are many different types of pools, including:

  • Above ground pools
  • Below ground pools
  • Freshwater pools
  • Saltwater pools

Now that we’ve ruled out the type of pool, let’s move on to the size of your pool.

Pool Size

Depending on the dimensions of the pool itself and its water volume, you will need a pool heater in a size that will sufficiently heat your entire pool. Otherwise, it may be heated unevenly and there will be cold spots, which could potentially cause your heater to need to work twice as hard and use more power.

We will talk more about how you can find the correct size for your pool heater ahead.

Heating Speed

One of the most important things to determine which pool heater you want to purchase is the rate at which heats the entire pool. When researching different pool heaters, make sure to search how long it takes for the water to be heated to 80°F using said pool heater. You won’t want to be waiting for hours just to go swimming!


You will want to keep in mind the climate you live in, as different climates make for different pool heater needs:

  • Northern climates: Have harsher winters than southern
  • Southern climates: Might be able to get year-round usage

Now, let’s move onto the next factor, your budget.


You should absolutely make a budget plan for the overall cost of the heater itself to avoid overspending and to give you a good idea of how much money you want to put into your pool heater. Also, you will need to keep in mind the maintenance costs; they may be low, but they are still present.

Laws and Regulations

Following your local laws and regulations on pool heaters may limit the choices or also require or disallow certain factors in addition to the heater itself. However, you always want to make sure you are not making an off-the-market or illegal purchase, as they could be dangerous and inoperable.

Manufacturer’s Recommendations

It’s always best to follow the manufacturer’s recommendations when looking for a pool heater, as this will:

  • Inform on intended use
  • Prevent accidentally purchasing an unsuitable heater

Next, we will be covering how you can find the correct size pool heater for your pool.

How to Find the Right Size of Pool Heater for Your Pool

Here’s the steps you can take to find the right size of pool heater for your pool:

  • Step 1: Multiply your pool’s width by its length to find its surface area
  • Step 2: Divide the surface area of your pool by three
  • Step 3: The answer you get is the minimal amount of BTU (British thermal units) needed to heat the pool. 

According to Pool Supplies Canada, each BTU raises the temperature of one pound of water by one degree Fahrenheit.

Types of Pool Heaters

There are different types of pool heaters to suit various needs and wants in regard to the heating and even cooling options of a pool. Some are higher in initial cost, while low in maintenance costs. There are also varying levels of eco-friendliness that may be a selling point for various heaters to some buyers.

Remember to consider individual needs and wants when selecting a heater, as well as what kind of pool it is being installed on. Check the manufacturer’s instructions on whether or not a particular heater is good for an above or below ground pool, as well as if it is safe to use for a saltwater pool. Also check local laws and regulations to ensure that the selection falls within standards.

Gas Heaters

Gas heaters operate with either natural or propane gas. Which one varies on the individual heater. Pumped water from the pool is brought inside the heater, where gas is combusted in order to heat the water and return it to the pool, similarly to how other gas-powered machinery works. 

Here are a few pros and cons to Gas Heaters:

Heats water in any weatherGas emissions
Heats water extremely quicklyNot eco-friendly
Low initial costsHigh operating and maintenance costs

The type of gas should also be considered, as propane gas typically costs 1.5x that of natural gas. Additionally, the cost of operating a gas heater is 7x that of a simple heat pump.

Electric Heaters

Electric Heaters operate with a heating element inside of them. Once the cool pool water is run over this element, it quickly warms the water and returns it to the pool. However, they are only good for small pools of up to 5,000 gallons or hot tubs.

The pros and cons to an Electric Heater is as follows:

Heats water in any weatherOnly suitable for small pools and hot tubs
Heats water extremely quicklyNeed access to an outlet or generator
Low initial costsHigh operating and maintenance costs
Easy installation

On average, an electric heater requires approximately $6/hr to operate, which is 6x that of the operating costs of a Heat Pump. They also are only useful for smaller pools and hot tubs, so anything too large is not going to be suitable in this selection.

Heat Pumps

Heat pumps bring in water from the pool and heat it using the surroundings and then pump it back into the pool warmer than it was before. There is a fan that draws in the outside air, and a liquid coolant creates a gas. The compressor within the heat pump then heats the gas and transfers that heat to the water.

Some pros and cons to Heat Pumps:

Maintains temperatureDoes not work well below 50°F
Low operating costsVery slow to heat
Can also cool

While heat pumps are becoming more popular extremely quickly, they are not quite as useful in northern climates due to the fact that they rely on ambient air temperature to help heat. Once the temperature falls to about 50°F, they stop being quite as effective on heating an entire pool. Additionally, they are twice as slow as a gas or an

electric heater, heating at only 1-2°F every hour.

Solar Heaters

Solar panels on a Solar Heater will collect the heat from the sun in order to heat the pool, as well as circulating cooler water during peak months in hotter climates. Pool water is pumped through a filter and into the Solar Heater, where it moves through the solar collector to warm and then be returned to the pool. They are the most eco-friendly option; however, they require well-lit areas and do not do well in wooded lots or in areas with a lot of rain.

Pros and cons to Solar Heaters:

No operating costsNeeds a lot of sunlight
SilentExtremely high initial costs
Extremely long warrantiesDifficult installation
Extremely eco-friendlyRelatively slow heating
Can also cool

Solar heaters may be the most ecological of the bunch, but they really need a pool in well-lit areas and require a lot of startup costs. Installing one should almost always be done by a professional, unlike the other options which can typically be installed alone. They also are the only ones to offer extremely long warranties and have no operating costs, so they balance themselves out and are attractive options to pool owners with a lot of sunlight to power them.

Unfortunately, in areas without a lot of sun, this eco-friendly option might not even be much of an option at all and needs to be considered. Additionally, they can also be considerably slower than some of the options, especially in areas with a lot of rain or cloud cover.

There are also solar blankets, which are extremely cheap pool covers which trap heat within the pool. They still have the issues of slow heating and needing a lot of sunlight. They can also end up being rather heavy, requiring multiple people to cover and uncover a pool before and after use.

Saltwater Heaters

Typically, any type of heater can have one that is suitable for a saltwater heater. Be sure to check the individual heater on whether or not a heater is suitable for a salt chlorine generator pool, which may be how it is listed instead of the simple phrasing of just saltwater.

Benefits of a Pool Heater

Installing a heater in a swimming pool has numerous benefits behind them, ranging from protecting the pool, having more time to spend with friends and family, all the way to personal health benefits. While typically not required, the benefits of having a pool heater far outweighs not having one, with the main drawback being additional operating costs for the pool. 

Protects the Pool

Even after a pool has been drained, some water will remain in the plumbing. A pool heater can make it so the water never freezes during the winter months. As the water is kept at a consistent temperature, there will be no fluctuating water within the pipes, reducing the risk of them becoming damaged due to changes in ambient temperature.

It can also make it so that, depending on climate, the pool may never need to be fully drained and thus keeps it protected from the elements.

Positive Investment Opportunity

A well-maintained pool adds value to a home, and therefore it stands to reason that a pool heater will help protect that investment. Due to the fact it helps protect the pool itself and has low maintenance requirements, adding a pool heater is an attractive addition to a pool, if just for the investment opportunities that lay with it.

They are also typically very durable and have long lives, meaning that there is quite a bit of bang for the buck when it comes to a pool heater.

Extended Swimming

The main reason pools get shut down in the first place is that the water gets too cold to be enjoyable, especially coupled with the cooler air in the fall. A heater extends how long a pool can be in use, all the way from a few additional months to enabling it to be used year-round in warmer climates.

Additionally, it also allows for night-time swimming, which is an experience in and of itself. 

Health Benefits

Swimming is an aerobic exercise that is low-impact and thus easy on the joints. The temperature also matters for blood circulation and easing the stiffness of joints in a way that isn’t going to cause as much trouble as a typical exercise would. Including a heater in the pool allows for various health conditions to safely exercise for more months out of the year than they would have otherwise been able to do.

Extended swimming times gives more time for friends and family, so allowing more months and longer use during those months gives even more time for that healthy social interaction.

Now that the benefits of having a heater in the first place are out of the way, let’s look at the different types of pool heaters, as well as the pros and cons of each type.


Adding a heater to a pool is a great way to extend the life of the swimming season, sometimes even making it usable year-round. This allows for more social time with friends and family, as well as numerous health benefits, especially for those suffering chronic conditions.

Additionally, it is best to thoroughly read the manufacturer’s recommendations after any heater has been selected, as they will have thorough explanations on how the heater is intended to be used. Where one brand of the selected type might not quite fit individual desires, another brand might have it while still offering the same benefits of that particular style.

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