Weil McLain 633-900-130 Residential Thermostat Refrigerant and the "20" is the

and the "20" is the temperature differential

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

allowing for precise cycling control and preventing excessive compressor wear

Versatile Compatibility: Fits standard 3/4 inch NPT piping and interfaces seamlessly with JCI actuators for automated building management

Weil McLain 633-900-130 Residential Thermostat Refrigerant and the "20" is theWhen 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