OBSERVATION ISOLATE MAINS WATER - DOES DEMAND STOP ?

Isolate Mains Power to appliance as per TOPs P4

Turn OFF the DHW isolation valve

WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure

Mains Power On

Observe the appliance does the demand for HW stop?

Note:
The valve is isolated when the screwdriver slot is in the horizontal position - as shown.