Honeywell Air pressure switch C6065FH1706U

This is a mechanical pressure switch (pneumatic relay) used in gas boilers and burners, particularly in Baxi equipment. It controls the presence of draft or air pressure: it allows gas supply and ignition only when the fan has created the necessary pressure. The switch blocks burner start-up in the absence of required air pressure. It is an original component with model C6065FH1706 and OEM equivalent 628610.

Parts of this type are selected by switching range, differential, connection type (threaded or hose spigot), and contact rating. Approvals relevant to the intended application should also be matched. Before installation, confirm that the range and connection match the original.

Common failure modes include a torn diaphragm, a blocked impulse tube, or a drifted setpoint. These typically cause burner lockouts that resemble ignition faults. Symptoms include the boiler not starting: the fan runs but ignition does not occur and an air pressure or draft error is displayed, or the burner starts but goes out after some time with a fan error. Verify the impulse line condition and switch operation.