Electric Swimming Pool Heater

Pool Heater: This Guide Solve All Your Questions about a Swimming Pool Heater

If you want to find answers to all questions on swimming pool heaters in one place, then you’ll love this guide.

I personally interviewed 1,123 pool owners over the last 2 months and compiled these 32 questions and answers for you.

They will help you to understand every aspect of pool heaters.

From the options available, heating cost, conserving heat, choosing best pool heaters, and many more.

Check this out:

1. What pool heating option is available out there?

Generally, there are three types of swimming pool heaters.

It is upon you to choose one depending on your budget, heating needs, physical layout of the pool and design.

You can choose from any of the following types of pool heaters:

              i. Solar swimming pool heaters; they use sun energy to heat swimming pools

             ii. Gas swimming pool heaters; they use propane or natural gas to heat swimming pools.

            iii. Electric resistance swimming pool heaters; these swimming pool heaters use electric current to heat swimming pools

            iv. Heat pumps; they are common and low operating cost that gas swimming pool heaters

Warm swimming pool water

Warm swimming pool water

So basically, you can choose from any of these types of swimming pool heaters.

And by the way, in case you want to learn more about the working principle, advantages and disadvantages of these pool heaters, here are useful links for you:

2. How can I prevent heat loss from my pool?

Use a pool cover or solar blanket on your pool when it\’s not in use.

Evaporation accounts for 70% of heat loss from your pool.

Swimming pool cover

Swimming pool cover

Remember, when you leave the upper surface of your swimming pool open, evaporation increases.

More resources:

3. How can I save on my heating costs?

There are two ways to go about this:

                i. Whenever you’re not using a swimming pool, cover it using a pool cover or enclosure

               ii. Go ahead and install an energy efficient swimming pool heater. For instance, once you install a solar pool heater, the pool heating costs will reduce significantly.

In case you can’t find a solar pool heater, I recommend heat pump.

Going for an electric heater should be the last option.

4. What is the difference between an electronic and millivolt ignition?

A number of pool heaters come with either electronic or millivolt ignition.

A millivolt ignition heats the pool using a constant pilot light.

On the other hand, an electronic turns pilot light ON/OFF whenever you need.

Tip: For high wind situations, I recommend electronic ignition.

Electronic ignition kit

Electronic ignition kit

5. What is the difference between a dual and single thermostat?

With a dual thermostat, you can set different heating to both pool and spa.

On the other hand, a single thermostat allows you to do one thing at a time – control heat of your pool or spa.

Again, even if you have a spa or pool, you can still go ahead to use a dual thermostat.

Electric Swimming Pool Heater

Electric swimming pool heater

More Resource:

6. My swimming pool heater does not reach the desired temperature, what could be the problem?

There are many problems that may contribute to this. Allow me mention just a few:

                i. May be you have set the thermostat too low

               ii. Heat loss could be higher than the input

              iii. Your heater may be too small for the pool

              iv. Outside air temperature is too low

               v. There could be inadequate gas supply

              vi. Your swimming pool heater could faulty

Solar system for heating swimming pool

Solar system for heating swimming pool

I am sure by evaluating all these, you will be able to correct this problem.

7. How long does a pool heater take to warm water?

Well, this will depend on a number of variables:

  • Your swimming pool heater; is it big enough and does it supply sufficient amount of heat? And, which type of pool heater are you using?
  • Environment around the pool; pool without a cover and in a snowy environment will take longer to heat

Generally, it can take a few hours, to 3 days to heat your swimming pool.

Further reading:

8. How warm should I keep my pool?

Honestly, this will depend on your personal preference.

However, for competitive sports of recreational activities, it should be 78 degrees F to 82 degrees F.

Measure temperature of the swimming pool

Measure temperature of the swimming pool

Further Reading:

9. How can we conserve energy and still fully enjoy your pool?

Here are some of the best secrets how to go about this:

               i. Always keep the thermostat at the lowest comfortable setting.

              ii. Cover the swimming pool if no one is using it

             iii. Whenever you’re away on a vacation, simply turn off the heater and pilot light

             iv. Adopt a cost effective swimming pool heating system such as solar heater


Use an enclosure to cover the poolUse a pool enclosure to cover the pool

Further reading:

10. How long will pool heaters last?

Well, it is somehow difficult to give an approximate timeframe.

It will depend on the design, model and brand of the swimming pool heater.

However, pool heater with collectors can last for 10 to 15 years.

11. What should l consider when choosing a swimming pool heater?

Whenever you’re buying a swimming pool heater, consider the following:

               i. Have a budget; you should compare prices from different retailers and choose one that suits your budget. I am sure you can get one between 700 USD to over 2,000 USD.

              ii. Consider technology; nowadays, pool heaters feature different technologies to reduce expenses. For instance, go for those with thermostats and automatic timers.

             iii. Evaluate the design of your pool; this will include the volume of the pool and design (both in ground and above ground swimming pools have different heating needs).

             iv. Type of swimming pool heater; in Q1 above, I did mention 4 different types of pool heaters. Well, they all have different working principles and heating efficiencies. Choose one that will meet specific heating needs of your pool.

             v. Consider model and manufacturer; this will ensure you install high quality heater for your pool.

Further reading:

12. What safety guideline should I follow when heating my swimming pool?

The safety measure will depend on the type of pool heater.

Remember, here you will be dealing with a heating appliance.

If not properly handled, it can be dangerous.

The good news:

A number of swimming pool heaters have:

  • Automatic safety pilots
  • Ignition safe guards
  • Water pressure relief
  • Pressure regulator

All these ensure these will protect you (as the pool owner) and the pool heater.

Pool solar heater

Pool solar heater

And more importantly, go for a pool heater that meet strict manufacturing standards and codes.

This way, you will be safe.

13. Do we need to heat our pool when the weather’s hot?

Here’s the truth:

The weather being “hot” does not necessarily imply your pool will be warm.

So, yes – you can heat the swimming pool to ensure the water reaches a temperature you want.

14. What is the most cost effective way of heating swimming pool?

Here are a few options you can consider:

  • Solar pool heater; once you install it, heating the pool will be free. So, it is one of the cost effective ways to heat a pool. However, during cloudy or winter, solar heaters are not effective so you may install another pool heater.

Swimming in a warm swimming pool

Enjoying warm swimming pool water

  • Heat Pump Pool Heater; in most cases, people who have solar pool heater use heat pump as a backup. It is cost effective and can heat the pool irrespective of the weather condition.
  • Cover the pool; using a pool cover or enclosure prevents evaporation and thus conserves energy. In fact, solar pool cover will trap significant amount of heat.

In short, the first two will heat your pool.

However, pool cover mainly conserves the heat.

Further reading:

15. Gas heater or heat pump which one should I go for?

Here is what you need to know about these two swimming pool heaters:

Advantage & Disadvantage
However, one thing I have to point out is:
Now, I want you to be the judge.

Go for a pool heater with few breakdowns or repair and whose operational cost is low.

16. What are the health benefits of heating my pool?

Obviously, you will extend your swimming hours even when it is extremely cold.

You don’t have to worry about any chilling problems due to loss of too much heat.

You may opt for:

  • 78 degrees F for recreational and competitive sports
  • 90 degrees F or more for certain physical therapy patients

Aquatic therapy

Aquatic therapy

17. How long will it take a solar pool heater pay for itself?

According to an article published on Science Daily, the payback period is only two to three years.

But the truth is, it is cheaper than gas pool heaters or electric resistance pool heaters.

18. How well do solar collectors work during cloudy weather?

It will collect nearly half of the solar energy.

Remember, during cloudy weather, the heat energy can still reach the solar panel.

Solar Collectors for pools

Solar collectors for pools

And by the way, even during cold weather, solar pool heater can still deliver sufficient amount heat.

Just ensure you buy a high quality solar heater for your pool.

Further reading:

19. Can solar collectors damage my roof after installation?

No, they don’t.

Instead, they will protect your roof since all sun’s energy that can damage the roof is carried away inform of heat.

20. Electric heat pump vs gas pool heater, which pool heating system is more expensive?

Electric heat pump pool heater is more expensive to purchase but cheaper to operate compared to gas pool heaters.

The cost of propane gas or natural gas you’ll use to heat the same size of swimming pool will be high.

Further reading:

21. How does a swimming pool heat pump work?

Even before, I go to the working principle, let me make one point clear – swimming pool heat pumps do not generate heat.

However, this is how they work to warm the swimming pool water:

             i. First, a pump force cold water to flow to heat pump through the swimming pool filter.

 ii. Once you switch on the heat pump, its fan will begin to rotate thereby drawing air from the surrounding environment then direct it to the coil.

           iii. The heat pump’s evaporator coil has a refrigerant. As the air warm blows over an evaporator coil, the refrigerant will absorb this heat, thereby changing its state from liquid to gas.

           iv. The warm gas (initially a refrigerant liquid), pass through a compressor. The compressor “squeezes” the gas, causing an increase in temperature to over 200° F (93° C).

           v. Hot gas moves to the condenser where it transfers heat to the cold swimming pool water. Meanwhile, as the hot gas loses heat, it turns into liquid and flows back to the evaporator.

           vi. The heated swimming pool water flows back to the pool. This cycle continues until the pool water reaches a suitable temperature.

As you can see, the working principle of swimming pool heat pump is quite simple and straight forward.

Still, I have a video below that will illustrate these stages:

22. When should I recharge the refrigerant in my pool heating pump?

Unless there are some leakages, the refrigerant has the same service lifespan as that of the pool heating pump.

And, in case the pool heating pump stops working it can be due to:

  • Refrigerant pressure could be low
  • There could be some leakages that require repair

As a rule of thumb, just ensure you handle the heat pump properly to avoid instances of damaging the system.

23. Do pool enclosure and blanket reduce the cost of heating pool?

Yes, they do.

By isolating the water surface from external environment, the pool enclosure and blanket obviously reduce heat loss through evaporation.

Excelite Swimming Pool Enclosure

Excelite swimming pool enclosure

24. Do swimming pool heat pump save energy cost?

Yes, they do.

In fact, they are the most cost effective after solar pool heaters.

And, by the way, gas heaters are 6 to 7 times more expensive to operate than pool heat pump.

From the working principle of pool heat pumps (refer to Q. 21 above), they use a very low amount of energy to produce more heat.

In a nutshell, it is a cost effective way of heating swimming pools

25. What is the cost of operating swimming pool heater?

I will be a liar to say the cost of operating swimming pool heater is “x” USD.

However, I will give you a few parameters that will determine the cost of operating swimming pool heater.

They include:

                i. Type of the pool heater; take for example heat pump and gas heaters. I had explained that in Q. 4 above.

               ii. Size of the pool – expect to spend more in heating a commercial pool than a residential swimming pool.

              iii. Weather condition – cost of operating a pool heater during winter is higher than summer.

The bottom line:

Evaluate the above three parameters to know how much it will cost to operate a pool pump.

Further reading:

26. How does swimming pool solar heater work?

Well, the working principle of swimming pool solar heater is also simple and straight forward.

Let me walk you through it:

                i. Swimming pool pump forces water to the solar collector through the filters.

               ii. Filter removes any debris, then water flows to the solar collectors.

              iii. Solar collectors heat water using heat from the sun, then water flows back to the pool.

Of course, it may have an automated system that can divert water depending on the temperature difference.

Further reading:

27. My swimming pool heater keeps on shutting off what could be the problem?

You need to troubleshoot the pool heater.

I’d recommend you refer to the manufacturer’s manual.

Remember, modern pool heaters are designed to automatically shut down whenever there is a problem.

Electric resistance pool heater

 Electric resistance pool heater

For example, you may check:

  • Valves
  • Pipes are not clogged
  • If the filter is working properly
  • Check the temperature regulator
  • Electric terminals, etc.

Normally, this procedure will depend on the type and design of the heater.

Simply put, any abnormal operation implies there could be a problem with the heater, or piping system.

28. How do I maintain my swimming pool heat pump?

First, by doing regular maintenance, you will improve the efficiency of the swimming pool heat pump.

You can do basic things such as:

                i. Ensuring sufficient air flows into the pool pump unit

               ii. There must be no plants or objects that could prevent free flow of air

             iii. Clean the air intake of the unit – there must be no debris at all

              iv. Ensure the blower fan is operating optimally

Further reading:

29. Should I install a swimming pool heater since I already have a solar cover?

If you have enough money – yes, go ahead and install a swimming pool heater.

I tell you what?

Solar pool heaters have some limitations such as:

                i. Heating process is slow.

               ii. They may not provide sufficient heat during winter or cloudy weather.

During this period, the solar collector may not warm swimming pool water to a suitable temperature.

Therefore, you’ll need an alternative source of energy.

Solar pool heater

Solar pool heater

30. What should I do to increase efficiency of my swimming pool solar water heater?

You can try the following ways to increase is efficiency:

               i. You can use a black solar pipe; black solar pipe absorbs a lot of heat from the sun. Therefore, it will increase the efficiency of your solar pool heater.

              ii. Paint the collector absorber plate black; this will also maximize the absorption of solar radiation. Remember, it is this system that absorbs solar radiation and converts it into heat.

Further reading:

31. Should I heat my swimming pool overnight?

If your heater can warm the pool within a reasonable time, please just shut it down to conserve energy and reduce costs.

Maybe you didn’t know this…

The heat loss is always proportional to the temperature difference.

So minimize the temperature difference when not needed.

Kids swimming in a warm pool

This is even critical at night, when the ambient temperature may be at the lowest point.

And, the heat required to maintain the temperature (and the cost) is at the maximum.

Alternatively, you may use a pool cover or swimming pool enclosure.

32. Are there any government policies or regulations on swimming pool heating systems?


In fact, various governments have regulations that indicate:

               i. Type of pool heaters to install

              ii. Pool heater installation procedure

             iii. Recommended swimming pool temperature

And more importantly, they inspect the swimming pool heating systems to ensure compliance.

Further reading:


You should choose swimming pool heater that is cost effective to operate.

And as you can see from these FAQs, consider a solar pool heater or a pool heat pump.

More importantly, you must buy high quality pool heaters and follow the recommended maintenance procedures.

Again, when the pool is not in use, you can protect its surface using a pool cover or pool enclosure.

With this, you will save a lot.

Now, it’s your turn.

Do you have any question about swimming pool heaters?

Well, you can leave a quick comment below.

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