Honeywell Printed circuit board SM11470U

This printed circuit board is a control board for modern wall-hung boilers and is intended for Westen applications. It uses ionisation flame detection and performs a lockout on flame failure. The board reads the heat demand signal, checks the air pressure switch, and accepts NTC sensor inputs. It also controls a three-way valve, a circulation pump, and the gas valve or air damper for modulation. This board is not interchangeable across different models.

Parts of this type are selected by exact series and type designation because they are matched to a specific boiler model. Before ordering, compare the supply voltage, safety time, pre-purge time, and flame detection method with the original. Verify the part number and the original boiler model, as two similar-looking boards may have different safety times. A mismatch is a safety hazard.