What does the Baxi Duo-tec F57 fault code mean?
The F57 fault code on a Baxi Duo-tec boiler indicates a domestic hot water (DHW) pressure fault. This typically means that the boiler is unable to maintain the required pressure for hot water delivery.
Common Causes
- Low Water Pressure: Insufficient water pressure in the system can trigger this fault, often due to leaks or insufficient filling.
- Faulty Pressure Sensor: A malfunctioning pressure sensor may incorrectly report pressure levels, leading to the F57 code being displayed.
Can I fix it myself? (DIY)
If you are comfortable, you can check the pressure gauge on the boiler and top up the system pressure if it is low (typically below 1 bar). However, if the issue persists or involves gas or electrical components, it is crucial to call a Gas Safe Engineer.
Estimated Repair Cost (2026 UK Prices)
The estimated repair cost for addressing the F57 fault could be around £150 to £250, depending on whether the issue is simply a pressure top-up or requires replacement of the pressure sensor, which can be more expensive.