What does the Worcester Bosch Greenstar CDi F51 fault code mean?
The F51 fault code indicates a problem with the expansion vessel in the Worcester Bosch Greenstar CDi boiler. This component is crucial for maintaining the correct pressure within the system, and a fault can lead to pressure fluctuations and potential system failure.
Common Causes
- Loss of Pressure: A drop in system pressure can cause the expansion vessel to fail, leading to the F51 error code.
- Membrane Failure: The internal membrane of the expansion vessel may have ruptured or degraded, preventing it from functioning properly.
Can I fix it myself? (DIY)
It is advisable to call a Gas Safe Engineer to address this issue, as working with gas appliances can be dangerous. Attempting to fix the expansion vessel without proper training may lead to further complications.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for replacing the expansion vessel is around £150 to £250, depending on the specific model and labour costs. This price reflects the need for professional installation and the cost of the part itself.