BoilerFaultCodesThe 6 most common faults
01
E 02 High DIY-safe
Your boiler has stopped working because it cannot move the water around the system effectively.
What to try first
Check your boiler pressure gauge; if it is below 1 bar, use the filling loop to top it up to 1.5 bar.Check if your central heating system is full of air by bleeding your radiators.Ensure all radiator valves are fully open to allow water to flow freely.
02
E 08 High DIY-safe
Your boiler has detected that the water level inside the heating system is too low to operate safely.
What to try first
Locate the external filling loop, which is a silver braided hose connected to two valves under the boiler.Slowly open both valves to allow mains water to enter the system until the pressure gauge on the boiler reads between 1.0 and 1.5 bar.Close both valves tightly and check for any leaks around the filling loop connections.
03
A 01 High Engineer
Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.
Full guide for A 0104
A 03 High Engineer
Your boiler is trying to start but cannot detect a flame, so it has safely shut itself down to prevent gas from building up.
Full guide for A 0305
A 37 High Engineer
Your boiler's internal computer has encountered a critical error and can no longer process instructions, meaning the unit cannot operate.
Full guide for A 3706
A 39 High Engineer
Your boiler has detected an internal electronic error within its main control brain, preventing it from operating safely.
Full guide for A 39on the Chaffoteaux Minima HE System 30
Central heating pumpPressure sensorFlow switchPressure gaugePressure relief valveFilling loop
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 Chaffoteaux 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