Gas vs Heat Pump vs Solar
The three ways to heat a pool trade off very differently: gas heats fast but costs the most to run, heat pumps are cheap to run but slow, and solar is nearly free to run but depends on sun and space. Your climate and how you use the pool decide the winner.
Side by side
| Gas Heater | Heat Pump | Solar | |
|---|---|---|---|
| Heating speed | Fastest — heats on demand, any weather | Slow — needs air above ~50°F | Slowest — depends on sun |
| Running cost | Highest — burns gas or propane | Low–mid — moves heat, does not make it | Near zero after install |
| Install cost | $1,500–3,000 | $2,500–5,000 | $3,000–7,000+ |
| Typical lifespan | 5–10 years | 10–15 years | 15–20+ years |
| Climate fit | Any climate, on-demand heat | Warm / mild climates | Sunny climates with roof space |
| Best use | Quick heat-ups, spas, short seasons | Holding temperature over a long season | Owners chasing lowest running cost |
The verdict
you want heat fast and on demand — a weekend warm-up, a spa, or a cold-climate short season — and you accept the highest running cost for that speed.
you want the cheapest way to hold a comfortable temperature across a long swim season in a warm or mild climate, and you can wait for it to warm the water gradually.
you have sun and roof or ground space, want the lowest running cost by far, and are fine with weather-dependent heating and a bigger upfront install.
Pros & cons
- Fastest heating, works in any weather
- Great for spas and quick warm-ups
- Lowest install cost of the three
- Highest running cost
- Shortest lifespan
- Burns fossil fuel
- Cheap to run
- Long lifespan
- Efficient for long swim seasons
- Slow to heat
- Struggles in cool air
- Higher upfront than gas
- Near-zero running cost
- Longest lifespan
- Clean, no fuel or high power draw
- Weather-dependent and slow
- Needs significant roof / ground space
- Highest upfront cost
Gas wins on speed but loses on running cost. Heat pumps are the cheapest to run for holding temperature over a long season in a mild climate. Solar is nearly free to operate but slow and space-hungry. Many owners pair solar or a heat pump for the season with gas for fast top-ups.
Common questions
What is the cheapest way to heat a pool?
Solar has the lowest running cost by far — close to zero once installed — but the highest upfront cost and it only works with enough sun. Among powered options, a heat pump is the cheapest to run because it moves heat rather than generating it.
Is a gas heater or heat pump better?
Gas heats much faster and works in any weather, which suits spas, short seasons, and quick warm-ups, but it costs the most to run. A heat pump is far cheaper to run and lasts longer, but it heats slowly and needs air above roughly 50°F, making it best for holding temperature over a long season.
How long do pool heaters last?
Gas heaters typically last 5–10 years, heat pumps 10–15 years, and solar systems 15–20 years or more. Lifespan depends heavily on water balance, usage, and maintenance.
Can I combine heating types?
Yes, and many owners do. A common setup pairs solar or a heat pump to hold temperature economically across the season with a gas heater for fast, on-demand top-ups when the water needs to warm quickly.