BoilerFaultCodesThe 6 most common faults
01
118 High DIY-safe
Your boiler has detected an issue with water pressure inside the system, causing it to flash an error and temporarily stop working.
What to try first
Locate the filling loop underneath your boiler.Open the valves slowly to top up the system pressure until the gauge reads between 1 and 1.5 bar.Close the valves tightly and reset the boiler.
02
133 High Engineer
Your boiler is trying to light up but is failing to detect a flame after a few attempts, so it has safely shut itself down.
Full guide for 13303
128 High Engineer
Your boiler is lighting up briefly, but the flame keeps going out after just a few seconds.
Full guide for 12804
125 High Engineer
Your boiler manages to start up, but the flame keeps going out after about a minute, leaving you without reliable heating or hot water.
Full guide for 12505
110 High Engineer
Your boiler has stopped working because a safety sensor has detected that it is running too hot.
Full guide for 11006
130 High Engineer
Your boiler's flame is unexpectedly going out while it is trying to run, which will leave you without heating or hot water.
Full guide for 130on the Baxi PLATINUM COMPACT 25 COMBI
Pressure relief valvePressure sensorExpansion vesselIgnition leadElectrodesGas valve
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
Boiler cover options
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.