A pool heater can extend the swimming season and make your pool more comfortable during cool mornings and evenings. The right choice depends on how often you swim, how quickly you want the water heated, your pool size and the utilities available at your property.
For most inground pools in Southern Ontario, the practical choice comes down to a gas heater or an electric heat pump.
Gas Pool Heaters
Gas heaters use natural gas or propane to heat pool water quickly. They operate effectively even when the outdoor temperature is cool, making them well suited to Ontario’s shorter swimming season.
A gas heater may be the best choice when:
- You want the pool heated quickly
- You swim mainly on weekends or occasionally
- You want reliable heating during cooler spring and fall weather
- Natural gas or propane is available
- You use a spa that requires higher water temperatures
Gas heaters generally cost more to operate than heat pumps, particularly when maintaining a high water temperature continuously. Using a pool cover can substantially reduce heat loss and operating costs.
Electric Pool Heat Pumps
A heat pump draws warmth from the surrounding air and transfers it to the pool water. It heats more slowly than a gas heater but is generally more energy-efficient once the desired temperature has been reached.
A heat pump may be suitable when:
- You maintain a consistent pool temperature
- You swim regularly throughout the season
- Energy efficiency is more important than fast heating
- The equipment area has adequate airflow
- You primarily use the pool during warmer weather
Heat pumps become less effective as the outdoor temperature drops. This can limit their usefulness during cold spring or fall weather in Ontario.
What Size Pool Heater Do You Need?
Pool-heater sizing is based on more than the volume of water. Important factors include:
- Pool dimensions and water volume
- Desired water temperature
- Typical outdoor temperatures
- Sun and wind exposure
- Whether the pool has a cover
- How quickly you want the water heated
- The size and length of the gas line
- Available electrical service
An undersized heater may run for long periods without bringing the water to the desired temperature. An oversized unit may cost more initially and could require utility upgrades that were not anticipated.
A qualified installer should review the pool and property before recommending a specific heater.
Why a Pool Cover Matters
A large amount of pool heat is lost through evaporation, especially overnight. A solar blanket or automatic pool cover helps retain heat, reduces evaporation and lowers the amount of time the heater must operate.
Even an efficient heater can be expensive to operate if the pool is left uncovered during cool or windy weather.
Replacing an Existing Pool Heater
A replacement heater is not always a straightforward swap. Before purchasing new equipment, confirm:
- The existing gas line is correctly sized
- Electrical connections meet current requirements
- The plumbing layout is suitable
- The equipment pad has adequate clearance and ventilation
- The new heater is compatible with the pool’s automation and salt system
- Local installation and venting requirements can be met
Choosing equipment based only on the price of the heater can lead to unexpected installation costs or poor performance.
Gas Heater or Heat Pump: Which Is Better?
Choose a gas heater if fast heating and reliable performance in cooler weather are the priorities.
Choose a heat pump if you swim frequently, maintain a steady water temperature and want greater energy efficiency during warmer weather.
The best option depends on how you actually use your pool—not simply which unit has the lowest purchase price.
Get Help Choosing Your Pool Heater
Earthworks Landscaping & Pools supplies and installs new pool equipment for homeowners in Burlington, Oakville and surrounding communities. We can review your pool, existing equipment and utility requirements before recommending an appropriately sized heater.
Explore our pool design and installation services or contact Earthworks to discuss a new or replacement pool heater.
