Pentair MasterTemp Pool & Spa Heater

This model is specifically engineered for smaller bodies of water, including spas, aboveground pools, and inground pools up to 15,000 gallons. If your pool exceeds this volume, you will likely need a higher BTU output unit to achieve efficient heating.

Yes, the MasterTemp 125 is certified for both indoor and outdoor installation. If you are installing it indoors, ensure you use the appropriate venting and follow all local building codes for gas-fired appliances.

The heater is available in both natural gas and propane versions. You must select the specific fuel type that matches your home's gas supply at the time of purchase, as they are not field-convertible.

The unit features a 1-1/2 inch plumbing connection, which is standard for most smaller pool and spa setups. Ensure your existing pool plumbing matches this size or that you have the necessary adapters before beginning installation.

A higher thermal efficiency rating means the heater converts more of the fuel it consumes into actual heat for your water, rather than losing it as exhaust. At 82%, this unit is highly efficient for its class, which helps reduce your overall energy consumption and operating costs.

Beyond the standard plumbing and gas line connections, you may need an air intake kit if you are installing the unit in a confined space. The specific part number for the air intake kit is 474845.