PRESSURE DIFFERENTIAL ASSEMBLY (NON RETURN VALVE)

Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4

Turn Hot Water Tap On

Set flow rate to approximately 6 litres/min
Attach temperature clamp to flow pipe as
indicated by the red arrow

Gas On

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

Mains Power On

Measurement:

Allow boiler to fire on DHW.

Using a temperature probe, measure the temperature difference between the flow pipe and the pipe at the back of the differential assembly.
Differential should be approximately 10°c or greater.

Rear view