Heating Element w/Gasket - Bolt-On Type - 120vThe WH1A-S is a screw in heating element that is 1250w at 120a designed to quickly and efficiently heat the water via electricity in a Raritan water heater.These elements must be installed, and the tank filled prior to applying any power or they will burn out. Raritan does offer an element that can last a bit longer if power is applied without water in the tank.