Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Set flow rate to approximately 3 litres a minute
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the fan run for a DHW demand?
Is a fan related fault code shown (2961 or 2962)?
Notes:
1. If a different fault code appears click HERE.
2. If the appliance DHW supply is fed from a solar heated cylinder CLICK HERE for additional information.