Gas pool heaters and heat pumps both warm pool and spa water, but they work differently and suit different habits. Answering a few questions before you buy makes it much easier to compare models and avoid surprises during installation.
How each one heats
- Gas heaters burn natural gas or propane to heat water as it passes through a heat exchanger. They can raise water temperature relatively quickly and do not depend on the outdoor air temperature.
- Heat pumps run on electricity and move heat from the surrounding air into the water. They generally heat more gradually, and their output depends on air temperature, so they tend to work best in mild weather. Some models can also cool the water.
Questions to answer first
How will you use the pool and spa?
If you heat a spa on short notice or use the pool occasionally, quick heat-up may matter most. If you want to keep the pool at a steady temperature through the season, gradual heating may be enough.
Which energy supply is available?
A gas heater needs a gas supply of the right type (natural gas or propane) and a gas line sized for the heater's input rating. A heat pump needs an electrical circuit that matches its voltage and amperage requirements. Check what your property already has. Adding gas line capacity or electrical capacity can change the scope of the project.
Where will it go?
Both types need space on or near the equipment pad. Each manufacturer specifies clearances, and gas heaters also have venting requirements. Heat pumps move a lot of air, so think about airflow and where the unit's sound will travel.
What flow will it get?
Heaters and heat pumps have minimum and maximum water-flow ratings. Your pump and plumbing should deliver flow within that range. Our pump guide explains how to gather your pump details.
Will it work with your controls?
Many heaters can be controlled by pool automation systems, but compatibility depends on brand and model. See our automation compatibility guide before you choose.
What do local rules require?
Gas and electrical work usually requires permits, and California has energy requirements that affect pool heating equipment. Confirm current requirements with a qualified installer before you buy.
Comparing models
When you compare spec sheets, look at heating capacity (BTU per hour), fuel or electrical requirements, flow range, physical size and clearances, heat-exchanger materials, control options and the manufacturer's warranty terms. Prefer figures from the manufacturer's own documentation over general claims.
Heater checklist
- Pool and spa volume, and how you plan to use each
- Available fuel (natural gas or propane) or electrical capacity at the pad
- Space, clearances and venting or airflow at the location
- Your pump's flow and your filter model
- Your automation system, if any
- The current heater's brand, model and age, if you are replacing one
Get help choosing
For help comparing heaters and heat pumps for your equipment, contact our team with your current setup. For professional installation in the Los Angeles area, see Showtime Pools' equipment installation and upgrades service. Installation and local delivery coverage depend on your address, so please confirm availability with our team before you order.