What does the Vaillant Home F31 fault code mean?
The F31 fault code on a Vaillant Home boiler indicates a pump fault, which typically means the pump is not functioning correctly or is blocked. This can lead to inadequate circulation of water within the heating system, affecting performance.
Common Causes
- Blocked Pump: Debris or sediment may be obstructing the pump, preventing it from operating effectively.
- Electrical Issue: A fault in the electrical supply to the pump could cause it to fail to start or operate intermittently.
Can I fix it myself? (DIY)
While you can check for blockages and ensure the pump is free from debris, it is strongly advised to call a Gas Safe Engineer for any electrical issues or if you are unsure, as working with gas appliances can be dangerous.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for a pump replacement on a Vaillant Home boiler is around £300 to £400. This includes the cost of the pump and labour, as it requires a qualified engineer to ensure safe and proper installation.