Ideal 075434 Logic Honeywell PCB

The Ideal 075434 is a logic printed circuit board supplied as a replacement control PCB for Ideal domestic boilers. It sits in the appliance's control box and carries the board-level electronics that run the boiler's operating sequence, including burner demand, fan and pump control, and the safety interlocks that shut the appliance down when a fault is detected. The board is built around Honeywell logic circuitry and is supplied by Ideal as a direct replacement for the original item.

• The boiler locks out repeatedly with no obvious external cause, or the lockout clears only after a power cycle.
• The display is blank, shows scrambled characters, or the boiler gives no response to a demand for heat or hot water.
• The fan, pump or diverter runs erratically, or the boiler fires and shuts down within seconds of ignition.
• Fault codes appear intermittently and change between resets, pointing to a control board rather than a single component.
• Visible damage on the board itself, such as scorching, a blown track, or a swollen capacitor.

• Read the part number printed on the existing board and match it to IDEAL075434 before ordering; control boards can look identical across revisions.
• Note the appliance's GC number and serial number from the data plate so the correct board variant can be confirmed.
• Check the board connectors and loom for heat damage or corrosion, as a damaged plug can cause the replacement board to fail in the same way.
• Isolate the appliance from the electrical supply before removing or fitting the control box.