The way a gas pool heater works is similar to a household furnace. A burner tray is ignited below an air space which heats up a series of copper-finned tubes. Your pool water is pumped through these copper tubes, which give up the heat to the water as it passes through.

To power a natural gas heater you have to run an underground gas line from the meter on your house (or a propane gas tank) over to the pool heater. The size of the gas line has to be sized correctly or the heater will not work properly. In order to determine the correct size gas line, measure the distance from the heater to gas meter. The further the distance, the larger the gas line that is required for the pool heater. There is also a secondary regulator that is installed just outside the pool heater, where the gas pipe enters. 

Gas pool heaters are the quickest way to heat your swimming pool, gas pool heaters heat the pool faster than pool heat pumps. You can raise the temp of a pool 1-3 degrees per hour, depending on it’s size, where heat pumps may only raise the temperature 1-3° per day! If this is a weekend home or you just plan on swimming on the weekends, or if you have an attached spa, and want to increase the temperature quickly- Go Gas.

An electric pool heater works in reverse of a central air conditioning unit. The way it operates is that it transfers heat from the outside air to your swimming pool water.  Warm air is drawn over the evaporator coil by the fan; water runs through the heat exchanger and comes back into your pool through your inlet.

To power an electric pool heater, you will need to install a dedicated 220v electrical circuit, on a 40 -60 amp circuitbreaker. If you currently have a 100 amp outdoor sub-panel breaker box at your equipment pad, you may have enough room to simply pop-in one of these large breakers. Open the sub-panel, look for the amperage rating, and then add up the amps of the existing breakers. Look for the amp draw of each breaker; printed numbers on each breaker switch.