Set Appliance State:
Set Multimeter to Resistance 
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Room Stat if fitted Calling
Room Stat if fitted Calling
Measurement:
Measure resistance across connection 3 (marked SWL) and connection 4 (marked L) on the main connector block.
Note:
If external controls are not fitted then a link should be present between the connections.
Note:
If external controls are not fitted then a link should be present between the connections.
