What does the Vaillant ecoTEC exclusive F55 fault code mean?
The F55 fault code indicates that the boiler is experiencing issues related to system pressure, which may prevent it from operating efficiently. This can lead to insufficient heating or hot water supply.
Common Causes
- Low System Pressure: This can occur due to leaks in the heating system or insufficient water in the system.
- Faulty Pressure Sensor: A malfunctioning pressure sensor may incorrectly report the system pressure, triggering the fault code.
Can I fix it myself? (DIY)
You can attempt to reset the boiler and check the pressure gauge. If the pressure is below 1 bar, you can re-pressurise the system using the filling loop. However, if you are unsure or if the issue persists, it is strongly advised to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F55 fault could range from £100 to £250, depending on whether the issue is a simple re-pressurisation or requires replacement of a faulty pressure sensor.