Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect the wires from the APS noting 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 across terminals 1 and 3 of the APS (back and left connections as viewed from the front).
Note:
If continuity is not obtained it is permissible to increase the pressure by 50%.
100 Pascals = 1mbar / 50 Pascals = 0.5mbar
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 across terminals 1 and 3 of the APS (back and left connections as viewed from the front).
Note:
If continuity is not obtained it is permissible to increase the pressure by 50%.
100 Pascals = 1mbar / 50 Pascals = 0.5mbar
Isolate as per TOPs P4
and refit as necessary