Home Pool Gas Heaters 10K - 20K gallons

Pool Gas Heaters

Pool gas heaters deliver fast, high-output heating for in-ground and above-ground pools and spas. Unlike heat pumps, gas heaters maintain full BTU output regardless of air temperature - making them the right tool for fast heat-up, cold climates, pool-spa combinations, or any setup where recovery speed matters. Models in this collection are available in natural gas and propane configurations to match your existing fuel supply.

Hayward Pool Gas Heaters - What to Know Before You Buy

Hayward's H-Series is currently the featured gas heater line in this collection. In-ground models run on 240V single-phase power with a 15-amp maximum breaker and 5.5 circuit amps. The 135K BTU above-ground models use 120V. Clearance requirements are 6 inches rear and 12 inches on each side. In-ground units connect via 2" x 2-1/2" CPVC union fittings, which makes replacement on an existing equipment pad straightforward. All models use a cupro nickel heat exchanger and low NOx combustion, and none require a high-wind stack for outdoor installation.

Choosing the Right BTU for Your Pool

Gas heater BTU sizing is primarily about recovery speed - how fast the heater can bring a cold pool up to temperature - rather than whether it can heat the pool at all. A smaller unit will still heat a larger pool, just more slowly. As a general guide for warm climates like Florida where pools hold heat well:

**Hayward H-Series BTU Sizing Guide**
Model	BTU Output	Pool Size Range	Pool Type
H135 (W3H135FDP / W3H135FDN)	135,000 BTU/hr	Up to 25,000 gallons	Above ground
H150 (W3H150FDP / W3H150FDN)	150,000 BTU/hr	Up to 35,000 gallons	In ground
H200 (W3H200FDP / W3H200FDN)	200,000 BTU/hr	Up to 45,000 gallons	In ground
H250 (W3H250FDP / W3H250FDN)	250,000 BTU/hr	Up to 50,000 gallons	In ground
H400 (W3H400FDP / W3H400FDN)	400,000 BTU/hr	Up to 80,000 gallons	In ground

In colder climates or for pools that sit unused for weeks at a time and need fast recovery, size up. For pool-spa combinations where fast spa heat-up matters, the 400K BTU model is worth considering regardless of pool size.

Natural Gas vs. Propane Pool Heaters - Which Should You Choose?

Every model in this collection is available in both natural gas and propane configurations. The units are identical in output, dimensions, electrical requirements, and warranty - the only difference is fuel type, and the two are not field-interchangeable without a licensed conversion. Natural gas is generally cheaper to run per BTU in most US markets, so if your home or property already has a natural gas line, that is the lower-cost choice over time. Propane makes sense when natural gas is not available at the installation site.

Pool Gas Heater vs. Heat Pump - What Is the Right Fit?

Gas heaters heat water faster than heat pumps and maintain full output regardless of air temperature. That makes them the better choice for pools that sit unused for long periods, pools in cold climates, spas that need fast recovery, or any setup where time-to-temperature matters more than energy cost. Heat pumps move heat from the air rather than burning fuel, which makes them significantly more efficient in moderate climates for day-to-day temperature maintenance. For Florida pools used regularly through a long swim season, a heat pump often has lower operating costs. For large pools, spas, or pools in colder regions, a gas heater - or a gas heater paired with a heat pump - is usually the better fit. If you want to browse heat pumps, see our pool heat pumps collection.

Frequently Asked Questions

Do these heaters work with saltwater pools?

Yes. All models in this collection use a cupro nickel heat exchanger, which resists saltwater and aggressive pool chemistry better than standard copper alternatives. That makes them a solid choice for salt chlorine generator pools and coastal installs.

Do gas pool heaters need a permit?

In most jurisdictions, yes. Gas appliance installation typically requires a permit and inspection, and the work must be done by a licensed contractor. Requirements vary by state and municipality - check with your local building department before scheduling installation.

Can these heaters be installed indoors or in an enclosure?

The in-ground Universal H-Series models support indoor installation with the appropriate Hayward indoor vent kit accessory. Outdoor installation does not require a vent stack. For enclosed or semi-enclosed outdoor setups, confirm combustion air requirements from the installation manual before finalizing the equipment pad location.

What warranty do these heaters come with?

All models in this collection include a 1-year parts warranty with no labor coverage. Installation, labor, and service costs are at the owner's expense. Review the warranty documentation linked on each product page before purchase.

Do you offer installation?

Yes. Visit our installation page for details on how we can connect you with a qualified installer in your area.

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