Worcester Bosch Error Codes
We know how frustrating a Worcester Bosch error code can be.
We know how frustrating it is when your Worcester Bosch boiler displays an error code.
Worcester Bosch Error Codes
Worcester Bosch boilers are designed to be reliable, but like any heating system, they can sometimes develop issues. Fault codes make it easier to identify what’s gone wrong by showing a code on the display. These error messages cover problems such as ignition failures, low pressure, faulty sensors, and overheating.
If your Worcester Bosch boiler error codes, don’t panic — some are quick fixes, like repressurising your system, while others may need a Gas Safe engineer to investigate.
Understanding Worcester Bosch Boiler Error Codes
Below you’ll find a list of the most common Worcester Bosch boiler error codes and what they mean, along with possible causes and fixes.
Meaning: No flame detected
Possible Cause / Fix: Gas supply issue, blocked flue, or faulty ignition – try resetting the boiler.
Meaning: Overheat
Possible Cause / Fix: Blocked heat exchanger or faulty temperature sensor – call a heating engineer.
Meaning: Fan or Air Pressure Fault
Possible Cause / Fix: Fan not running or issue with air pressure switch – engineer required.
Meaning: Sensor fault
Possible Cause / Fix: Flow temperature sensor error – check sensor or wiring.
Meaning: Ignition faults
Possible Cause / Fix: Boiler not lighting correctly – may need ignition parts checked or replaced.
Meaning: Pump issues
Possible Cause / Fix: Circulation pump not working properly – service may be required.
Meaning: Low water pressure
Possible Cause / Fix: The system pressure has dropped below the required level (usually under 1 bar). Check the pressure gauge and repressurise the boiler if needed.
Meaning: Fan running slowly
Possible Cause / Fix: Fan fault or motor issue – technician needed.
Meaning: Low water pressure
Possible Cause / Fix: Check pressure gauge (should be 1–1.5 bar) – repressurise if needed.
Meaning: DHW sensor fault
Possible Cause / Fix: Domestic hot water sensor problem – replace sensor.
Meaning: Heat Control Module fault
Possible Cause / Fix: PCB issue or communication error – may need parts replaced.
Meaning: Low water pressure lockout
Possible Cause / Fix: Boiler has locked out due to low pressure – repressurise system.
Meaning: Flow temperature sensor fault
Possible Cause / Fix: Faulty sensor – replacement often required.
Meaning: Fan or Air Pressure Switch Fault
Possible Cause / Fix: Similar to E5 – fan or air pressure switch fault – engineer needed.
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