Viessmann 7856004 Pump Head 322838-752 Fuel Flexibility: Enables reliable unit

Fuel Flexibility: Enables reliable unit heater operation in off-grid or rural locations using liquid propane

Smith 100172003 Gas Valve Assembly is a critical OEM component designed for high-efficiency negative pressure regulation in Knight KBN150 and AWN150 series boilers

Manual Reset Safety: Prevents uncontrolled restarts after safety circuit interruptions

Spring Return Failsafe: Ensures the damper returns to the start position during power interruptions

or diagnostic codes on the boiler control board indicating ignition failure or lost flame signal

Viessmann 7856004 Pump Head 322838-752 Fuel Flexibility: Enables reliable unitThe Viessmann 7856004 Pump Head is a precision engineered Grundfos UPS15 78 B1KA replacement designed for high head hydronic applications. This boiler circulation pump assembly is the OEM solution for restoring hydraulic balance in Viessmann Vitodens 100 W and 200 series condensing boilers. Featuring a 3 speed motor configuration, this wet rotor circulator allows for fine tuning the flow rate to match the specific friction loss of the heat exchanger