Set Appliance State:
Gas Off
Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Observation:
Remove the modulation box end plate and using a screwdriver blade apply light pressure to the modulation arm ensure that the modulation arm and mechanism is free to move inside the modulation box.
Note:
Ensure gas soundness on re-assembly
Note:
Ensure gas soundness on re-assembly
Isolate as per TOPs P4
and refit as necessary