Boiler displays F.63, will not start, sometimes after power surge

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Corrupted PCB memory, Incorrect PCB fitted, Electrical surge damage, Software error

Safety: Isolate power before accessing electronics.

Power reset: Turn off power for 5 minutes and then restore. If F.63 remains, the PCB is likely faulty.
Check supply quality: If there have been recent power cuts or surges, consider fitting a surge protector.
Engineer replacement: The main PCB will usually need to be replaced and configured with Vaillant diagnostic tools by a qualified engineer.

Professional Required 5/5

Main Control PCB

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