Honeywell Gas boiler control unit S4565D3023U

This control box is an automatic gas burner control unit for use in gas boilers, heaters, and water heaters. It operates on a 220–240 V supply and supports both direct burner ignition (DBI) and pilot burner ignition (IP) systems. The unit communicates directly with Honeywell VK41 series gas regulators via a dedicated top connector. It provides preset extended ignition time and a manual reset lockout for safety. The control box is designed in accordance with EN 298 and EN 60730-1.

Control boxes of this type are selected by matching the supply voltage, ignition system type (direct or pilot), and the gas regulator series. They attach to the regulator through a dedicated connector at the top; it must align with the regulator's mating connector. These units may be installed within a 90° angle in any direction from the vertical position of the two-position electric actuator. Before ordering, verify that the control box model is approved for the specific gas regulator model in the equipment.

When this type of control box fails to sense a flame within the safe ignition time, it enters a lockout state requiring a manual reset. The reset can be performed with the built-in or external reset button, or by interrupting the power supply; wait at least 15 seconds between reset attempts. If the airflow control relay does not detect sufficient airflow during pre-purge, the unit remains in standby with the fan running. A flame loss during operation triggers a restart sequence with pre-purge; repeated interruptions may indicate a faulty flame sensor or wiring.