Optimum Pool Technologies High Limit Switch Replacement for Pentair MasterTemp & Max-E-Therm Heaters - Replaces 42001-0063S

The Pentair Sta-Rite High Limit Switch is an important switch in your Max-E-Therm or MasterTemp pool heater, and is used to detect when your water temperature has exceeded a safe level (135°F) and immediately opens the heat exchanger outlet when that happens. You MasterTemp heater will indicate when it is time to replace the High Limit Switch when the "HLS" LED is displayed. Compatibility: Pentair Max-E-Therm, MasterTemp Heaters. Replaces: 42001-0063S, STA-151-6255.