Honeywell Gas boiler control unit S4560B1006U

This gas boiler control unit provides burner ignition and flame supervision for gas-fired atmospheric burners. It features a manual reset lockout and a reset button that is accessible either externally or internally. The unit is maintenance-free and requires external fuses for safe operation. Its protection class is IP40. After a failed reset, wait at least 15 seconds before the next attempt.

Control boxes of this type require external fuses to be fitted in the supply circuit. The installation must provide at least IP40 protection. When replacing, verify that the reset button access arrangement matches the equipment layout, and consider fitting a maximum thermal relay to shut off the unit in case of overheating.

Typical failure modes include lockout when the flame is not established within the safe ignition time, causing the burner to stop until the reset button is pressed. If the flame is lost during operation, the control repeats the ignition sequence. If a combustion product relay triggers, all valves close and a manual reset is required. Check the reset button and allow at least 15 seconds between reset attempts.