Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the air pressure switch from the boiler
(make a note of the connections)
(make a note of the connections)
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 to that indicated on the pressure switch, Continuity should then be measured between common (black probe) and normally open (red probe) connections on the air pressure switch.
Note:
If continuity is not obtained, it is permissible
to increase the pressure by 50%.
100 Pascals = 1mbar / 50 Pascals = 0.5mbar
Increase the pressure to that indicated on the pressure switch, Continuity should then be measured between common (black probe) and normally open (red probe) connections on the air pressure switch.
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