BoilerFaultCodesThe 6 most common faults
01
E133 High DIY-safe
Your boiler has failed to ignite the gas needed to heat your water and home, so it has safely shut itself down.
What to try first
Check if your gas supply is working by testing another gas appliance like a hobEnsure your gas meter credit is topped up if you have a prepayment meterPress the 'Reset' button on the front of the boiler for at least 3 seconds
02
E119 High DIY-safe
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
What to try first
Locate the external filling loop, usually consisting of a small flexible hose with one or two valves underneath the boiler.Open the valve(s) slowly to let water into the system until the pressure gauge on the front of the boiler reads between 1.0 and 1.5 bar.Close the valve(s) tightly and check for any leaks.
03
E110 High Engineer
Your boiler has detected that it is overheating and has automatically switched itself off to prevent damage.
Full guide for E11004
E20 High Engineer
Your boiler's temperature sensor is failing, which prevents it from correctly monitoring how hot the water inside the system is getting.
Full guide for E2005
E28 High Engineer
Your boiler's flue sensor is failing to provide accurate temperature readings, so the system has shut down as a safety precaution to prevent overheating.
Full guide for E2806
E50 High Engineer
Your boiler is unable to read the temperature of the water it is heating, so it has turned off the hot water supply to prevent overheating.
Full guide for E50on the Baxi Duo-tec Combi HE
Ignition electrodeGas valvePCBPressure Relief ValvePressure SensorExpansion Vessel
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Baxi shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue