Extend The Swimming Season: Pool Heaters Explained!

There are several ways to heat a swimming pool. Much of it depends on the following...

  • Where you live. How hot does it get in your area? How cold does the swimming pool water get at night?
  • What is your idea of warm water? How hot do you want to get the water? Is this for the swimming pool only or is this also for a spa as well?
  • Local utility costs. What your local fuel vs electrical costs are. Which is cheaper in your area?

Once you have some answers to those questions we can recommend a heating solution for your swimming pool. For most people the practical choice is between a gas heater and a heat pump.

Gas heaters are generally best if you want to heat the pool occasionally.

Heat pumps if you want to keep the pool heated for long periods. 

Here are some options that take into consideration the different ways to heat a swimming pool or spa suitably for your family. 


Gas Heaters

Gas heaters burn either natural gas or propane to create heat. Gas burns inside a combustion chamber, which contains a series of copper coils. As the gas burns, water passes through the coils and heats. Gas heaters have historically been the most widely-used swimming pool heaters, though their popularity is decreasing due to high gas prices and the efficiency of heat pumps.

Advantages of Gas Heaters

  • Inexpensive to purchase
  • Operate independently of air temperature. In other words it doesn't matter how cold it is outside these heaters will keep the pool water warm. 
  • Heat pool or spa water quickly

Disadvantages of Gas Heaters

  • Expensive to operate: monthly operating costs between $300 and $500, especially if you want to keep a pool warm through very cold temps. 
  • Not energy efficient: COP between 0.80 and 0.85
  • Lifespan of five years
  • Not environmentally friendly: emit air pollution

Heat Pumps

Heat pumps use electricity to transfer heat to your swimming pool. Air-source heat pumps transfer heat from the air, and water-source (geothermal) heat pumps transfer heat from water. Because of their energy-efficiency, heat pumps have rapidly grown in popularity.


Advantages of Heat Pumps

  • Inexpensive to operate: monthly operating costs between $50 and $150
  • Energy efficient: COP between 5 and 6
  • Water-source heat pumps: operate independently of air temperature
  • Lifespan of ten to 20 years
  • Environmentally friendly: use renewable energy source and emit no air pollution

Disadvantages of Heat Pumps

  • Expensive to purchase
  • Air-source heat pumps: dependent upon air temperature, in other words these will only work to a certain temperature. If it is 20 degrees outside and you want to heat your spa it won't work. 
  • Heat pool water slowly, must plan far in advance to heat he the pool water.

Solar Heaters

Solar heaters use solar panels to transfer heat from the sun to your swimming pool. As solar panels sit in the sun, they collect heat. Then, the swimming pool pump pushes water through the circulation system and through the solar panels. As the water passes through the solar panels, it heats. Because of solar heaters’ reliance on the sun, many swimming pool owners use auxiliary heaters during nights and cloudy days.

Advantages of Solar Heaters

  • Inexpensive to operate: no additional monthly operating costs
  • Energy efficient: operate with your pool pump
  • Lifespan of 15 to 20 years
  • Environmentally friendly: use renewable energy source and emit no air pollution

Disadvantages of Solar Heaters

  • Expensive to purchase
  • Dependent upon sun: must be facing south sun without shade from trees, cannot operate at night and will not operate in cloudy weather.
  • Heat pool water very slowly
  • Unattractive installations on swimming pool owner’s roof or lawn

Remember: a swimming pool heating system is a big investment. If, after reading this article, you are still unsure which heating system is right for you, let Classic Pools help! Contact us directly or leave us a comment below.