General information, not legal, engineering or insurance advice.
Texas homeowners who heat a pool usually choose between three options: an electric heat pump, a gas heater(natural gas or propane), or solar pool heating. Each has advantages and disadvantages, and the right choice depends on where you live, how often you swim and what fuel you have at the house. Here's how each one works and what to weigh, based on U.S. Department of Energy guidance.
How a pool heat pump works
A heat pump doesn't burn fuel. It uses electricity to capture heat and move it from one place to another, in this case from the outdoor air into your pool water. It does not generate heat itself.1
- Running cost: heat pump pool heaters generally cost more to buy than gas heaters, but they typically have much lower annual operating costs because they are more efficient.1
- Air temperature matters: because a heat pump draws its heat from the air, it works best when the air is mild. The Department of Energy says heat pump pool heaters work efficiently as long as the outside air stays above roughly the 45°F–50°F range.1 On cold nights and during winter cold fronts, more common in North Texas and the Panhandle than on the Gulf Coast, it delivers less heat and may take longer to bring the pool up to temperature.
- Lifespan: with proper maintenance, heat pump pool heaters typically last longer than gas pool heaters.1
How a gas pool heater works
Gas pool heaters burn natural gas or propane to heat the water directly.2 Their strengths are speed and independence from the weather:
- A gas heater is most efficient when heating a pool for short periods and is well suited to heating a pool quickly.2
- That makes gas a good choice for pools and spas that are not heated on a regular basis.2
- Unlike heat pumps and solar, gas heaters can hold a set temperature regardless of the weather.2
The trade-off is fuel. Running cost depends on your natural gas or propane price and how much you heat. If you don't have natural gas service, a propane tank and delivery are part of the picture. Gas heaters also have venting and clearance requirements, and local air quality or building rules can affect which models are allowed, so ask your contractor what applies where you live.
How solar pool heating works
A solar pool heating system pumps pool water through solar collectors, usually on the roof, and returns it warmer. In pool systems, the swimming pool itself is the storage, and the pool's filtration pump circulates the water through the collectors. Unglazed polymer (plastic) collectors are typical for pool heating.4
- Operating cost: the Department of Energy describes solar pool heaters as cost competitive with gas and heat pump heaters, with a low annual operating cost.3
- Site: you usually need an unshaded area facing south, southeast or southwest, such as a roof.4Output depends on sunshine, so cloudy spells and short winter days mean less heat.
- Backup: most people don't use a backup heater with solar pool heating. Spas are the exception: owners may heat both pool and spa with solar but use a backup heater to get the spa hotter.4
Side-by-side
| Heat pump | Gas | Solar | |
|---|---|---|---|
| Heat-up speed | Slower; depends on air temperature | Fast | Depends on sunshine |
| Holds temperature in any weather | No | Yes | No |
| Purchase cost | Generally more than gas | Generally less than a heat pump | Get quotes |
| Operating cost | Typically much lower than gas | Depends on gas or propane price | Low |
| Lifespan | Typically longer than gas | Ask the manufacturer | Ask the manufacturer |
| Best fit | Pools used often in mild weather | Occasional use, fast heat, spas | Sunny roof, lower running cost |
Based on the comparisons in sources 1–4. Actual costs depend on your equipment, utility rates and how you use the pool.
What drives operating cost
Whatever you choose, a few things have a big effect on how much heating costs:
- A pool cover. Evaporation is by far the largest source of a pool's energy loss, and pool covers can save 50% to 70% of pool heating costs.3
- Your set temperature. The Department of Energy points to keeping pool temperatures at the lower end of the recommended range (78°F to 82°F) as a way to manage energy costs.3
- Energy prices. Your electricity rate and time-of-use plan (heat pump) or natural gas or propane price (gas heater).
- Wind, shade and season length. A windy, shaded pool loses heat faster, and heating longer into fall and spring costs more.
Questions to ask before you choose
- Which type do you recommend for how often I use the pool, and why?
- How did you size it? Please show the calculation (see our sizing guide).
- Does my electrical panel, gas supply or pump need upgrades, and is that in the quote?
- Who pulls the permit, and are electrical, plumbing or gas permits needed?
- What do the manufacturer warranty and your labor warranty cover, and for how long?
- Are you licensed for this work? Check the number on the TDLR license search (see our hiring guide).
Sources
- U.S. Department of Energy, Energy Saver, “Heat Pump Swimming Pool Heaters”.
- U.S. Department of Energy, Energy Saver, “Gas Swimming Pool Heaters”.
- U.S. Department of Energy, Better Buildings, “Pool Efficiency” fact sheet.
- U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, “A Consumer’s Guide: Heat Your Water with the Sun” (DOE/GO-102003-1824, December 2003).