Heating turns a summer-only pool into one you can use for much of the year. In California, where many coastal pools stay cool even in summer and inland pools get chilly in spring and fall, heating is one of the most important equipment choices. It is also one of the biggest drivers of running cost.
The three main options
Gas heaters (natural gas or propane)
- How it works: Burns gas to heat water passing through a heat exchanger.
- Strengths: Heats water fast, works in any weather, and is ideal for spas and occasional use.
- Weaknesses: Highest operating cost per hour of heating in most cases. California's air quality districts regulate emissions from new gas pool heaters, so models sold here must meet low-NOx limits.
- Best for: Spas, quick heat-ups and owners who heat only occasionally.
Heat pumps
- How it works: Uses electricity to move heat from the air into the water, like an air conditioner in reverse.
- Strengths: Much more efficient than gas over time, especially in California's mild climate.
- Weaknesses: Higher purchase price than a basic gas heater. Heats more slowly. Less effective in cold air. May need an electrical panel upgrade.
- Best for: Owners who want to keep the pool warm for long seasons.
Solar pool heating
- How it works: Pumps pool water through collectors, usually on the roof.
- Strengths: Lowest running cost, since the sun provides the heat. Long-lasting systems.
- Weaknesses: Needs enough sunny roof area. Heats slowly and depends on the weather. Often paired with a heat pump or gas heater as backup.
- Best for: Sunny inland areas and owners extending the season rather than swimming in winter.
Choosing by California region
- Coastal (Bay Area, coastal LA, OC, San Diego): Mild air temperatures suit heat pumps. A cover is essential because cool nights pull heat out of the water.
- Inland Southern California and the Central Valley: Hot summers mean little summer heating. Solar is very effective for spring and fall.
- Desert (Coachella Valley, high desert): Solar and heat pumps work well, and summer heating is rarely needed.
- Northern and mountain areas: Shorter seasons. Gas or a combination system may make sense.
What affects heating cost
- Pool size and depth.
- Target temperature (each degree higher costs more).
- Wind exposure and shade.
- Whether you use a cover. A cover is often the single biggest saving, since most heat loss comes from evaporation.
- Your utility rates and time-of-use plan.
Don't forget the pump
Heating only works when water circulates, so pump efficiency matters. California's appliance efficiency rules require most replacement residential pool filter pumps to be variable-speed or multi-speed, and these use far less electricity than old single-speed pumps. See the California Energy Commission's appliance efficiency program for details.
Saltwater vs chlorine: a related decision
Many new California pools use saltwater chlorination. A salt cell makes chlorine from dissolved salt, so the water feels softer to many swimmers and you buy less chlorine. Trade-offs include the cost of the system, periodic cell replacement and the potential for salt to affect some natural stone and metal surfaces. Some local agencies also have rules about draining salt water, so ask your builder. Traditional chlorine systems have lower up-front costs. Either approach works, and the choice is mostly about feel, convenience and budget.
Incentives and rebates
Utilities and local programs sometimes offer rebates for efficient pool pumps, heat pumps or solar heating. Programs change often, so check your electric utility's rebate page and ask your builder what is currently available.
Bottom line
For most California pools, a heat pump or solar system paired with a good cover gives the best balance of comfort and running cost, while gas makes sense for spas and quick heat-ups. Ask builders to estimate heating costs for your target temperature and season, and compare options from licensed builders in our directory.
Finding a pool builder near you
Our directory covers every California city with at least 20,000 residents. Each city page ranks local pool builders by Google rating weighted by review count, so a builder with hundreds of strong reviews ranks above one with a handful. Where we could confidently match a business to the Contractors State License Board's public license file, we show a CSLB License Verified badge with the license number. Use the filters on each city page to narrow the list to gunite, fiberglass, spa, remodel or decking specialists, then request quotes from at least three builders.
Frequently asked questions
What is the cheapest way to heat a pool in California?
Solar heating usually has the lowest running cost, followed by heat pumps. Using a pool cover reduces heating costs whichever system you choose.
Is a heat pump or gas heater better?
Heat pumps are cheaper to run in mild weather. Gas heaters heat faster and work in any weather, which is why they are popular for spas.
How long does it take to heat a pool?
It depends on size, the heater's output and the weather. Gas heaters work fastest, while heat pumps and solar take longer.
Are saltwater pools better than chlorine pools?
Neither is better for everyone. Saltwater feels softer and reduces chlorine purchases, while chlorine systems cost less up front.
This guide is general information, not legal, tax or financial advice. Costs vary by property and builder. Last updated November 2026.