Weil McLain 633-900-130 Residential Thermostat Refrigerant Expandable Design: Ships in a

Expandable Design: Ships in a collapsed format for easy storage and expands easily into the existing cabinet guide rails

and the "20" is the temperature differential

This right-angle mount actuator operates within a standard 8-13 PSI spring range

Constant Duty Performance: Specifically designed for intermittent and continuous ignition cycles without overheating

System Reliability: Minimizes thermocouple dropouts and ignition delays by providing a steady heat source for the flame sensor

Weil McLain 633-900-130 Residential Thermostat Refrigerant Expandable Design: Ships in aWhen you're servicing or installing Weil McLain Plus or Gold Plus series indirect fired water heaters, maintaining thermal accuracy is non negotiable for system longevity and prevents short cycling. The Weil McLain 633 900 130 Residential Thermostat kit is an essential OEM replacement part designed for a precise operating range of 90F to 160F. This aquastat control integrates directly with factory configured drywells, ensuring the sensor bulb makes