Lochinvar & A.O. Smith 100277781 Control 326058-755 The pilot-operated mechanism uses the

The pilot-operated mechanism uses the refrigerant pressure differential to assist the valve in opening

When should this O-ring be replaced

provided the liquid conductivity falls within the 10K ohm sensitivity threshold

this thermistor ensures the control board receives precise analog signals to modulate capacity and manage thermal load

ensuring calibrated gas flow and optimal BTU output for consistent combustion

Lochinvar & A.O. Smith 100277781 Control 326058-755 The pilot-operated mechanism uses theThe Lochinvar 100277781 Control (Model FB751 1251) is an integrated control board engineered specifically for Crest Heating Boilers. As a critical OEM replacement part, this module manages the firing sequence, ignition control, and safety parameters for high efficiency hydronic systems. This model is a direct boiler part replacement for units with serial numbers beginning with 4015, ensuring seamless integration with existing HVAC wiring harnesses and