What does the Vaillant ecoTEC pro F90 fault code mean?
The F90 fault code on a Vaillant ecoTEC pro boiler indicates that there are faulty system customizations, which may affect the boiler’s performance and efficiency. This issue typically arises from incorrect settings or configurations that have been applied to the system.
Common Causes
- Incorrect Installation Settings: If the boiler was not set up according to the manufacturer’s specifications, it can lead to the F90 fault code.
- Software Issues: Outdated or corrupted software within the boiler’s control system may also trigger this fault code.
Can I fix it myself? (DIY)
It is recommended to call a qualified Gas Safe Engineer to address this issue, as it may involve complex system customizations that require professional expertise.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for resolving the F90 fault code is around £150 to £250. This cost typically covers a service call and any necessary adjustments or software updates to rectify the system customizations.