Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect wires from APS
Remove APS from boiler
Attach crocodile clips to exposed spades on the APS
Remove APS from boiler
Attach crocodile clips to exposed spades on the APS
Measurement:
Note the operating pressure indicated
on the pressure switch.
Connect the air pressure switch charge kit to
P1 on the air pressure switch.
Ensure the performance tester reads 0mb.
Short circuit (zero resistance) should be measured.
Slowly increase the pressure via the syringe.
Short circuit should continue to be measured until the pressure is equal to that indicated on the pressure switch, at which point the resistance should change to open circuit.
Notes:
100Pa (Pascals) = 1millibar
on the pressure switch.
Connect the air pressure switch charge kit to
P1 on the air pressure switch.
Ensure the performance tester reads 0mb.
Short circuit (zero resistance) should be measured.
Slowly increase the pressure via the syringe.
Short circuit should continue to be measured until the pressure is equal to that indicated on the pressure switch, at which point the resistance should change to open circuit.
Notes:
100Pa (Pascals) = 1millibar
Isolate as per TOPs P4
and refit as necessary