Boiler displays E1 338, often after power surges or wiring changes.

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 configuration, Power surge damage, Incorrect parameter settings, Faulty PCB

Safety first: Turn off power before opening the boiler casing.

Power cycle: Isolate the boiler for 5 minutes, then restore power to see if the error clears.
Check supply quality: Ensure the boiler is supplied from a stable mains source and that there are no loose connections at the isolator.
Engineer tasks: A Worcester Bosch-trained engineer may need to reprogram or replace the PCB and verify all configuration parameters according to the boiler model.

Professional Required 5/5

Main Control PCB

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