Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the air pressure switch from the appliance
Measurement:
Note the operating pressure indicated on the pressure switch.
Connect the air pressure switch charge test kit to P1 (+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 on the air pressure switch.
(Check embossed diagram on switch).
Note: If continuity is not obtained, it is permissible to increase the pressure by 50%.
100 Pascals = 1mbar / 50 Pascals = 0.5mbar
NOTE:
The design of switches may vary from appliance to appliance.
Connect the air pressure switch charge test kit to P1 (+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 on the air pressure switch.
(Check embossed diagram on switch).
Note: If continuity is not obtained, it is permissible to increase the pressure by 50%.
100 Pascals = 1mbar / 50 Pascals = 0.5mbar
NOTE:
The design of switches may vary from appliance to appliance.
Isolate as per TOPs P4
and refit as necessary