Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Gain access to PCB (use Insulation Mat as required)
Disconnect wires from APS making a note of their connections
Disconnect wires from APS making a note of their 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, disconnect the -ve connection.
Increase the pressure via the syringe to that indicated on the pressure switch. Continuity (zero resistance) should then be measured across the Common and NO terminals at the APS.
Notes:
If continuity is not measured it is permissible
to increase the pressure by up to 50%
If continuity is measured make a note of the pressure and keep air pressure switch charge kit connected to air pressure switch.
Connect the air pressure switch charge kit to +ve connection on the air pressure switch, disconnect the -ve connection.
Increase the pressure via the syringe to that indicated on the pressure switch. Continuity (zero resistance) should then be measured across the Common and NO terminals at the APS.
Notes:
If continuity is not measured it is permissible
to increase the pressure by up to 50%
If continuity is measured make a note of the pressure and keep air pressure switch charge kit connected to air pressure switch.
Isolate as per TOPs P4
and refit as necessary