How much does it cost to fix Baxi error code 117?

Typical repair cost for the Baxi 117 fault is £80-160 including labour.

117 Medium

Baxi 117 Fault Code

Q: What does the Baxi 117 fault code mean?

Your boiler has too much water in the system, which puts extra stress on the internal parts and may cause it to shut down for safety.

The Baxi 117 fault code means: your boiler has too much water in the system, which puts extra stress on the internal parts and may cause it to shut down for safety.. It appears on 26 Baxi models in our database.

Technical description: Water pressure too high

What causes the Baxi 117 fault?

This fault occurs when the water pressure inside your system has risen above the safe operating limit. The most common reason is that the filling loop valve used to top up the boiler has been left slightly open or is leaking water into the system. It can also be caused by a failure in the expansion vessel, which is meant to handle the natural pressure increases that happen when water is heated.

Typical repair cost £80-160 (including labour)

DIY fix possible

Check that the filling loop valves are fully closedSwitch off the boiler and allow the system to coolBleed water from a radiator using a bleed key to reduce pressureMonitor the pressure gauge until it returns to between 1.0 and 1.5 bar

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Baxi models that show the 117 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi 117 fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026