Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect leads from the air pressure switch noting the connections
Measurement:
Note the operating pressure indicated on the pressure switch.
Connect the air pressure switch charge kit to +ve connection on the air pressure switch.
Increase the pressure via the syringe to that indicated on the pressure switch. Continuity should then be measured
between common and normally open terminals (front and back connections) on the air pressure switch.
If continuity is measured, make a note of the pressure required for use in the next test.
Connect the air pressure switch charge kit to +ve connection on the air pressure switch.
Increase the pressure via the syringe to that indicated on the pressure switch. Continuity should then be measured
between common and normally open terminals (front and back connections) on the air pressure switch.
If continuity is measured, make a note of the pressure required for use in the next test.
Isolate as per TOPs P4
and refit as necessary