Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect one of the orange leads from the Air Pressure Switch
Measurement:
Measure resistance across the terminals of the Air Pressure Switch marked 1 and 2.
Expect continuity / zero resistance.
Is the resistance measured as expected?
Note:
Some appliances will not have an air pressure switch fitted, if this is the case select "resistance as expected" option below.
Expect continuity / zero resistance.
Is the resistance measured as expected?
Note:
Some appliances will not have an air pressure switch fitted, if this is the case select "resistance as expected" option below.
Isolate as per TOPs P4
and refit as necessary