Electric Pool Heaters: Here’s What You Need to Know



Getting into a freezing cold pool is no fun at all — no matter what time of year it is. So if you live somewhere that tends to get a bit brisk at night or frosty in the fall, a pool heater might be just what you need.

Not only will you be able to extend your pool season by weeks (if not months), you’ll be able to enjoy early morning and late-night swims without freezing your cheeks off.

Types of Electric Pool Heaters

All heaters and coolers, regardless of where they are located, work under the same basic principle of heat transfer. I’m going to refer to heaters only, however, from here on out because that’s what you’re interested in, right? 

What happens when you take a pot of water and put it on a hot stove?

The pot of water heats up. This is the heat exchange principle at work in which the heating element transfers heat to the surrounding area and heats whatever it comes in contact with. 

This same principle applies to your pool. You just won’t be able to make soup with it. 

In your pool, the heating element is surrounded by pipes that pump your pool water through. The heating element transfers the heat to the pool water and then the water is then returned to your pool, giving it a nice toasty feeling, perfect for a dip. 

The difference in electric pool heaters comes from the heat source or the heating element. The two major types that you’ll encounter are:

  • Electric Pool Heaters
  • Electric Pool Heat Pumps

Let’s start with electric pool heaters.

Electric Pool Heaters

An electric pool heater is just the generic term for any pool that uses an electric heating element to heat your pool. There are some different types but again, the same principles apply. 

Electric pool heaters use electricity to heat the heating element (usually metal coils). Pool water is then pumped around the coils to steal the heat away and return it to your pool. 

Have you ever looked inside a toaster while waiting for your breakfast to pop out and noticed the metal coils within heat up? That’s basically what’s happening here. Electricity is doing all the work. 

Electric Pool Heat Pumps

Electric heat pumps do something a little bit different. They use electricity but not to directly heat your pool. Heat pumps take heat from somewhere else and transfer it into the pool water. 

Don’t worry, there’s not a literal Robin Hood Heat Avenger stealing heat from other pools and adding it to your own. Heat pumps usually take heat from the surrounding air by compressing and decompressing refrigerant at different stages. 

It’s a lot to take in, but the moral of the story is that heat pumps use electricity, but they use a lot less to steal heat from elsewhere versus making it by themselves. 

Electric Pool Heaters

I like to think of toasters when I explain electric heaters. It’s a great visual and who hasn’t made toast?

Electric pool heaters are fairly simple, operationally speaking. They have a series of heated coils within them that are powered directly by electricity. As the coils heat up, water is pumped around the coils and heat is transferred into the water, which goes back into your pool, all nice and warm.

The Good, the Bad, and the Toasty

They also use a lot of electricity to get the job done, so you’re going to notice a jump in your electric bill when you use it. Depending upon your climate, you may not have many other options to heat your pool. The advantage of a pure electric heater is that they work in all temperatures. 

Electric pool heaters are typically ideal for spa owners since there is less water to heat. However, if you’re not worried about your utility bill and you want warm water fast, these can be a good option.

When choosing one for your pool, you’ll want to pay close attention to the wattage they use. They can cost anywhere between $3-$10 per hour to run. 


  • Cheaper initial expense than other options
  • Ideal for spas, rather than pools
  • They work in all temperatures


  • Use more electricity, causing higher utility bills over time
  • Less energy-efficient overall
  • Have lots of component parts, may need frequent repair

Electric Heat Pumps

Before we talk about the good and the bad, let’s look at the cycle of heat pumps. 

Heat pumps work in two cycles using two different coils for compression and decompression. Inside the heat pump is a refrigerant, similar to the stuff in your fridge or air conditioning unit. 

In phase one, the refrigerant is allowed to evaporate, becoming a gas that absorbs heat from the surrounding air. 

Phase two compresses the air from one coil and transfers it into the second coil where all of the absorbed heat is released. This is where the pool water is pumped around the heated coils to transfer the heat to your pool. 

The cycle then repeats, pumping the refrigerant back into the first coil to evaporate and absorb more heat. 

The Good, the Bad, and the Versatile

Electric heat pumps are the new kids on the block. As consumers become gradually more environmentally-conscious, there are more and more options in appliances that leave a smaller carbon footprint. Electric heat pumps use a lot less electricity than their counterparts and do a pretty good job at heating too.

They do have some issues, however. 

Remember when I told you that they take heat from their surrounding area? So then what happens when it’s really cold outside and there’s no heat to take?

The simple answer is: there’s no heat to take.

Although environmentally-friendly and much cheaper to operate, if you find yourself needing to heat a pool in temperatures around 50 degrees Fahrenheit, you may have some trouble heating the pool quickly.

Another point worth mentioning about heat pumps is the initial cost. If you’re simply doing a price point comparison between a heat pump and a traditional electric pool heater, the electric heater is always going to be the cheaper option, based on actual cost-to-buy.

That doesn’t mean they’re cheaper in the long run, however. If you plan on using your heater a lot, the money saved by a heat pump outweighs the initial cost. The cost to run a heat pump based on electricity alone is under $1 an hour. That’s pretty reasonable in the scheme of things.


  • Energy-saving and environmentally-friendly
  • Best for pool owners in warmer year-round climates
  • Lower utility costs over time


  • More expensive initial cost than electric pool heaters
  • Less efficient in cold or extreme temperatures

A Balmy Swim in No Time 

Electric pool heaters or pool pumps are a great investment to extend your swim season and to be able to actually use your pool during the early morning and late-night hours. If you think about it, getting a pool heater is really just a way to get to enjoy your pool more often (and be more comfortable doing it).

Whichever type you choose, electric pool heaters are a great option for keeping your pool at a toasty temperature. Just don’t forget to use a pool cover! These will keep the heat in longer and save you some bucks in the long run. 

Categories: Pool Care, Pool Equipment