Ceme Water pressure switch 54120N00006

This is a water pressure switch for Ferroli boilers. It is suitable for the DOMIcompact, DOMIcompact B, Domina E/Piezo, and GN2 N models. The switch monitors water pressure in the heating system and signals the burner or boiler control board when pressure is not within a safe range. This helps protect the heat exchanger and other components from low or high water pressure.

Parts of this type are selected by the required switching range, the differential (the difference between the switch-on and switch-off points), the type of connection (thread size or hose spigot), and the electrical contact rating. When replacing such a switch, verify that the setpoint is adjusted correctly for the system. Install the switch with the impulse line free of debris and ensure the electrical connections match the original wiring.

Typical failures include a torn or stiffened diaphragm, a blocked impulse tube, or a drifted setpoint. These can cause lockouts that may be mistaken for ignition problems. Check the diaphragm, impulse line, and setpoint if the burner locks out or fails to start.