E5
Worcester Bosch
Fan / Airflow Fault
Boiler displays E5, often associated with fan or air pressure issues on certain Worcester Bosch boilers.
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
Failed fan motor, Blocked flue or condensate, Faulty air pressure switch, Loose fan wiring connector
How to Fix / Troubleshooting
Safety first: Isolate power. Do not remove the sealed combustion cover or flue components unless Gas Safe registered.
- Listen for fan operation: On a heat demand, you should hear the fan start. If not, the fan may be failed or not receiving power.
- Check flue terminal and condensate: Ensure the flue outlet is clear and the condensate pipe is not blocked or frozen.
- Reset the boiler: After confirming no obvious external blockage, reset once. If E5 returns, stop resetting.
- Engineer tasks: An engineer should test the fan supply voltage, check the air pressure switch and tubing, and replace the fan assembly if necessary.
Advertisements
Repair Difficulty
Professional Required
5/5
Advertisements