Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove fan assembly and condensing heat exchanger adaptor

Observation:

Inspect flue adaptor running from the condensing
heat exchanger to the flue.
It should have no signs of
deterioration or condensate leakage.
Please refer to Technical Safety Advice Bulletin
in ADAPT for more information.
Note:
Take care as appliance may be very hot.