Set Appliance State:

Turn Hot Water Tap On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to ignite and run with a DHW demand for several minutes varying the flow rate during this period.
Does original fault code reoccur or is DHW operating satisfactorily?
Note.
If a fault code other than the original occurs CLICK HERE.