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 (zero resistance) should then be measured between common and normally open terminals on the air pressure switch.
Note:
35 CDi II appliances may have APS fitted
inside combustion chamber next to fan.
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 (zero resistance) should then be measured between common and normally open terminals on the air pressure switch.
Note:
35 CDi II appliances may have APS fitted
inside combustion chamber next to fan.
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