Honeywell Gas boiler control unit S4561D1001U

The Honeywell S4561D1001U is a gas boiler control unit designed for automatic ignition and control of atmospheric burners, compliant with EN 298. It operates on a supply voltage of 220–240 V AC and is intended for use with gas fuel. This control box features a non-volatile lockout type, ensuring safety in the event of a fault. It provides flame supervision and ignition control for gas burners.

When selecting a replacement control box of this type, ensure the supply voltage matches the system (e.g., 220–240 V AC) and that the fuel type is compatible (gas). The lockout type (volatile or non-volatile) must align with the burner's safety requirements. Verify the mounting dimensions and connector types to fit the existing wiring and enclosure. Always compare the model number and specifications with the original unit before installation.

Common failures in gas boiler control units include failure to ignite, intermittent operation, or lockout without reset. Symptoms may include the burner not starting, the system shutting down unexpectedly, or the control box not responding to reset attempts. Check for blown fuses, loose connections, or faulty flame sensors, and ensure the supply voltage is within the specified range.