this specific part is calibrated for natural gas applications

ensuring a seamless fit for technicians performing field retrofits or repairs

including high-performance YCJD and DR series units

Technicians should look for visible burn marks on the PCB

Key Benefits R-410A Optimization: Specifically designed to handle the higher operating pressures of 410A systems without compromising shell integrity

AERCO Boiler and Water Heater 18557-1 Tstat 321702-401 this specific part is calibratedThe AERCO 18557 1 Pneumatic Bulb Thermostat is a critical OEM replacement part designed specifically for AERCO boiler and water heater systems. This RA 20 240 thermostat utilizes advanced pneumatic sensing technology to ensure the precise temperature regulation required for commercial heating environments. By providing dependable sensing through its bulb style design, the 18557 1 Tstat maintains peak efficiency and prevents the energy waste associated