Ceme Water pressure switch 5230AA05

This is a Ceme water pressure switch with SKU 5230AA05. It has a 3/8" connection thread and is used to monitor water pressure in boiler heating systems. It ensures the pressure remains within the permitted operating band to prevent dry firing or overheating. When pressure falls below or exceeds the set threshold, it opens or closes an electrical contact, which the burner control interprets as a signal to interrupt or permit operation. This switch is designed to fit Ferroli Pegasus D, Pegasus D LN, Pegasus D K, and Atlas D models.

Parts of this type are selected by the connection thread size (for example 3/8") and by the pressure switching range and differential. The contact rating and approval class must also match the application. Before ordering, compare the thread type and the pressure settings, which are normally not adjustable on simple switches of this kind. Ensure the replacement has a compatible impulse tube and is mounted on the hydraulic circuit.

Common failures include a torn diaphragm, a blocked impulse tube, or a drifted setpoint. These typically cause lockouts that may be mistaken for ignition problems. When the switch fails, the burner may not start or may shut down unexpectedly. Check the impulse tube for blockages, test the diaphragm, and verify the setpoint against the system pressure.