Gas pool heaters typically heat faster and heat hotter than either heat pumps or solar heater installations for residential pools. Gas heater BTU output typically ranges from 250,000 BTUs to 400,000 BTUs or 2 to 3 times the max BTU output of a residential heat pump. They also can operate in nearly any temperature range that Florida is exposed to, enabling homeowners to heat their spa or pool to their desired temperature regardless of the ambient air temperature.

In addition to being the default option for heating spas, gas heaters are also frequently used as a secondary heating source on pools with a combined heating system such as a solar heater or a heat pump in use as the primary pool heater. In such a combined system, the gas heater would only turn on when the ambient air temperature dropped to a level below the heating capacity of the primary solar heater or heat pump, thus taking over for the primary system as it deactivates. 

Because gas heaters require a fossil fuel to operate you will have to separately install and manage the equipment for the gas supply lines. This often entails contacting a municipal gas utility or local company to have them run a gas supply line to your property and to setup the supply lines for your various appliances. It also may entail installing an on-site propane tank for those communities where an underground gas supply utility doesn’t exist. 

Gas pool heaters come in both liquid propane and natural gas burning varieties but you will need to know which type of fuel you will be using before you make a gas heater purchase. 

They have small space requirements in general but gas heaters must have clearance at least 4 feet horizontally away from windows and doors and vents into buildings as a precaution against carbon monoxide entering a home or facility. 

Gas heaters are an extremely common pool appliance and are the default recommended product for heating in ground spas and as the best option for a low temperature secondary heating source for combined heating source pools.