Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove both yellow leads from water pressure switch
Measurement:
Measure resistance across terminals of water pressure switch.
Note:
Water pressure switch has three terminals, one of which is not used and should be covered with plastic sleeve.
Note:
Water pressure switch has three terminals, one of which is not used and should be covered with plastic sleeve.
Isolate as per TOPs P4
and refit as necessary