Clean the piezo and thermocouple

Spark test, then clean the tips

The Essentials Guide (which shows the thermocouple) and the help centre. Both tips are at the right-hand end of the burner, at the back, reached through the mouth.

1. Detach the regulator and wait 5 minutes.
2. Push and turn the knob slowly to the click, and watch or listen for a spark at the right-hand end of the burner. A spark means the ignition works and any problem is the gas.
3. With the oven cold, lift the stone out: it makes the tips easier to reach.
4. Wearing gloves, blast compressed air at the piezo tip to clear soot, flour and debris (help centre).
5. Wipe the thermocouple with a dry paper towel. If you cannot reach it, blow it clean (Essentials Guide).
6. Put the stone back, reconnect, leak test and light it, holding the knob in for 5 seconds.