What does the Worcester Bosch Greenstar i F35 fault code mean?
The F35 fault code on the Worcester Bosch Greenstar i indicates a problem with the air pressure switch, which is responsible for monitoring the airflow in the boiler. This fault can prevent the boiler from operating safely and efficiently.
Common Causes
- Blocked Flue: A blockage in the flue system can restrict airflow, causing the air pressure switch to fail.
- Faulty Air Pressure Switch: The switch itself may be defective or malfunctioning, leading to incorrect readings.
Can I fix it myself? (DIY)
It is recommended to call a Gas Safe Engineer to diagnose and repair the issue, as working with gas appliances can be dangerous. Attempting to fix the air pressure switch without proper training may lead to further complications.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for fixing the F35 fault code is around £150 to £250, primarily due to the cost of replacing the air pressure switch and the labour involved in diagnosing the issue.