Baxi E117 Fault Code: Causes, Symptoms, and Step-by-Step Fix
The Baxi E117 fault code is a common error that indicates your boiler’s water pressure is too high. When the system exceeds its safe limit, usually above 2.5–3 bar, the boiler shuts down to prevent damage. Understanding this fault, its causes, and how to fix it can save you time, money, and stress.
Table of contents
What Does the Baxi E117 Fault Code Mean?
The Baxi E117 fault code activates when the water pressure in your heating system exceeds safe levels. Excess pressure can strain critical parts such as the pipes, seals, and heat exchanger. Prolonged high pressure may lead to leaks, system shutdowns, or costly repairs.
Normal Baxi Boiler Pressure:
- Cold system: 1.0–1.5 bar
- Operating system: Should not exceed 2.5 bar
The boiler regulates pressure using the expansion vessel and pressure relief valve, which absorb fluctuations and release excess water pressure.
Common Causes of the Baxi E117 Fault Code
The E117 fault is usually caused by:
- Overfilling the system – Adding too much water via the filling loop.
- Faulty filling loop – A leaking or improperly closed loop can increase pressure.
- Expansion vessel issues – A faulty or waterlogged vessel cannot absorb pressure changes.
- Pressure relief valve problems – A stuck or faulty valve can fail to release excess pressure.
Symptoms of the Baxi E117 Fault Code
Signs that your boiler has an E117 fault include:
- The boiler displays E117 on the control panel
- Loss of heating and hot water
- Radiators may heat unevenly or become too hot
- Unusual noises, such as hissing or gurgling
- Potential water leaks from the boiler or nearby pipes
Step-by-Step Guide to Fix the Baxi E117 Fault Code
Time needed: 3 minutes
Fixing the E117 fault on a Baxi boiler involves the following steps:
- Turn Off the Boiler
Switch off the power to your boiler to prevent any safety risks.
- Check the Pressure Gauge
Locate the pressure gauge on your boiler. If the reading is above 2.5–3 bar, the system is overpressurized.
- Release Excess Pressure
Open a radiator bleed valve to release some water and reduce pressure.
Keep an eye on the pressure gauge until it drops to the safe range (1–1.5 bar cold). - Secure the Filling Loop
Check that the filling loop valve is completely closed to prevent further pressure increases.
- Inspect for Faulty Components
If high pressure persists, inspect or replace:
Expansion vessel (may need recharging or replacement)
Pressure relief valve - Power the Boiler Back On
Once the pressure is back in the safe range and valves are secure, switch the boiler on. Monitor it for any recurrent error codes.
- Schedule Regular Maintenance
Prevent future E117 faults by:
Checking the pressure gauge regularly
Using the filling loop correctly
Arranging annual servicing by a Gas-Safe engineer
Conclusion
The Baxi E117 fault code is a safety feature that prevents damage due to high water pressure. By understanding its causes, symptoms, and step-by-step fixes, you can restore your boiler safely and avoid costly repairs. Regular maintenance and proper use of the filling loop are key to keeping your boiler running efficiently.
Frequently Asked Questions
ERROR CODE: E17. ERROR TYPE: Error on Temperature Sensor for Return Sensor. PROBABLE CAUSE: No temperature is detected by the temperature sensor for returning water.
The “T17″ Baxi boiler error code indicates a fault related to the heating return sensor. This issue typically arises when the sensor is either short-circuited or disconnected.
The E131 fault code Baxi is a safety warning that appears when your boiler detects that the flue or system flow temperature is too high.
