Set Appliance State:
Mains Power Off
Set Multimeter to DC Volts 
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Test 1:
With external controls turned OFF measure the voltage across the top two connections on connector CN4 marked 'Room stat'.
Expect 16 Vdc.
Test 2:
With external controls turned ON measure the voltage across the top two connections on connector CN4 marked 'Room stat'.
Expect 0 Vdc.
Note:
If no external controls are fitted a link should be present between the two 'Room stat' terminals of CN4.
With external controls turned OFF measure the voltage across the top two connections on connector CN4 marked 'Room stat'.
Expect 16 Vdc.
Test 2:
With external controls turned ON measure the voltage across the top two connections on connector CN4 marked 'Room stat'.
Expect 0 Vdc.
Note:
If no external controls are fitted a link should be present between the two 'Room stat' terminals of CN4.
