High
Lockout on Chaffoteaux 80/100

Your boiler has stopped working because it failed to light or stay lit, and it needs a manual restart to try again.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Lockout / flame failure (Red indicator 24 lights). Possible causes include the boiler being turned off for some time. Requires manual reset using the reset button (25).

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Pilot light keeps going out

Older boilers — thermocouple, draught, gas supply.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →