Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Isolate cold water feed to boiler
Open a hot water tap to release any pressure
Remove DHW filter/restrictor cartridge from the right hand flow group.
To remove filter/restrictor turn in anticlockwise direction and pull outwards
Note.
Take precautions to protect against water spillage whilst
carrying out this inspection.

Observation:

Inspect the filter and flow restrictor for blockages and damage