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Pentair Pool Heaters

This collection holds 30 Pentair pool heaters, all gas-fired, spanning the MasterTemp and Max-E-Therm lines. 21 run on natural gas and 9 on propane, with models sized for inground pools (19), above-ground pools (6), and commercial applications (5). Heat exchangers across the range include cupro-nickel (13 products) and titanium (1 product).

Start with the fuel line already running to your equipment pad — natural gas and propane heaters are not interchangeable, though some Max-E-Therm models are convertible between the two. Next, match BTU input to your pool volume and desired heat-up time: the sample MasterTemp units here range from 125,000 BTU (rated up to 15,000 gallons, in-ground or above-ground) up to 400,000 BTU for larger bodies of water. Also confirm plumbing size and gas connection against your existing lines, and check max flow rate against your pump's output — the 125K BTU MasterTemp units max out at 70 GPM, while the 250K–400K BTU units and Max-E-Therm models handle up to 120 GPM.

Within the range, the MasterTemp 125K BTU units are the compact option, at 100 lb with a 21 x 23 x 21 in cabinet, and come in cord-included or hardwire versions. The larger 250K and 400K BTU MasterTemp heaters step up to a cupro-nickel (HD) heat exchanger and a rustproof cabinet at roughly 133-136 lb. The Max-E-Therm 333K and 400K BTU models add a Dura-Glas rustproof enclosure and are the only units here with published thermal efficiency figures (82-84%), alongside Low NOx emissions and a wider 33-120 GPM or 40-120 GPM flow range depending on model.