What to Consider Before Choosing a Pool Heater
- Pool size and water volume
- Above ground or inground pool type
- Your climate and outdoor temperatures
- How quickly you want the water heated
- Energy efficiency and operating costs
- Available utility connections such as natural gas, propane, or electricity
- Whether you want eco-friendly heating options
- Available installation space
Types of Pool Heaters
Gas pool heaters are one of the fastest ways to heat a swimming pool. They use either natural gas or propane to quickly raise water temperatures and are commonly recommended for colder climates and larger pools.
- Large inground pools
- Cold climates
- Fast heating performance
- Pools used year-round
- Can heat water approximately 1–3°F per hour
- Requires natural gas line or propane supply
- Works effectively even in colder temperatures
- Higher operating costs than heat pumps or solar
- Low NOx models are more energy efficient and environmentally friendly
Electric resistance heaters use electricity to directly heat the water as it passes through the heater chamber. These systems are generally best suited for small pools and spas.
- Hot tubs and spas
- Small pools
- Warm climates
- Limited installation space
- Typically heats water more slowly than gas heaters
- Requires a nearby 240V electrical connection
- Generally lower upfront cost
- Higher day-to-day operating costs
- Less effective in cold weather
Pool heat pumps use electricity to transfer heat from the surrounding air into the pool water. They are one of the most energy-efficient heating options available.
- Warm to moderate climates
- Customers prioritizing energy efficiency
- Long swim seasons
- Reducing long-term operating costs
- Very energy efficient
- Quiet operation
- Lower operating costs than gas heaters
- Higher upfront purchase cost
- Performance decreases in temperatures below 60°F
Solar pool heaters use the sun’s energy to naturally warm pool water through solar collectors or panels. They are the most environmentally friendly heating option and have extremely low operating costs.
- Sunny climates
- Environmentally conscious pool owners
- Lower long-term operating costs
- Extending the swim season naturally
- Very low operating costs
- Requires adequate sun exposure
- Works more slowly than gas heaters
- Requires significant installation space
- Can last 15–20+ years with proper maintenance
Above Ground vs Inground Pool Heaters
Pool heaters are often designed specifically for either above ground or inground pools. Above ground pools are generally smaller and require lower BTU outputs, while inground pools typically require larger heaters for efficient heating performance.
- Above Ground Pools: Typically use smaller heaters with lower BTU requirements
- Inground Pools: Usually require larger heaters with higher heating capacities
Pool heater size is measured in BTUs (British Thermal Units). The larger the pool, the more BTUs required to efficiently heat the water.
- Smaller above ground pools may require approximately 45,000–100,000 BTUs
- Most inground pools use heaters between 200,000–500,000 BTUs
- Gas heaters generally require approximately 100,000 BTUs per 10,000 gallons of pool water
- Cold climates or pools without solar covers may require larger heaters
- Higher BTUs generally provide faster heating performance
Improve Heater Efficiency with a Solar Cover
Using a solar pool cover alongside your heater can help retain heat overnight, reduce evaporation, and improve overall heating efficiency. Solar covers can significantly reduce heat loss and help lower heating costs.
Frequently Asked Questions
Which type of pool heater heats the fastest?
Gas pool heaters generally heat water the fastest and are often preferred for rapid heating performance.
What is the most energy-efficient pool heater?
Heat pumps and solar heaters are generally considered the most energy-efficient pool heating options.
Can I use a heat pump in cold weather?
Heat pumps work best in warmer climates and become less efficient when outdoor temperatures fall below approximately 60°F.
Are solar pool heaters worth it?
Solar heaters can provide extremely low operating costs and long-term savings in sunny climates, especially when paired with a solar cover.
How do I know what size heater I need?
Heater sizing depends on your pool size, climate, desired heating speed, and whether you use a solar cover.