F0
Worcester
General Internal Fault / Sensor Range Error
Boiler displays F0, internal fault, may be associated with sensor or PCB issues, boiler may lock out.
Advertisements
Safety Warning
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.
Advertisements
Possible Causes
Out-of-range Worcester NTC sensor, wiring harness fault, intermittent PCB failure, poor earthing
How to Fix / Troubleshooting
Safety first: Turn off power before any internal inspection.
Homeowner checks:
- Power cycle the boiler and see if the code clears.
- Check that the boiler is properly earthed and that the supply is stable (no frequent tripping).
Engineer checks:
- Read out diagnostic data (if available) to identify which sensor is out of range.
- Test all NTC sensors (flow, return, DHW) for correct resistance.
- Inspect wiring looms for damage or loose connectors.
- Replace the faulty sensor or the Worcester PCB if confirmed defective.
Because F0 is generic, systematic testing is required; this is best handled by an experienced engineer.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Flow Temperature Sensor (NTC)
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements