Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
On/Off Switch ON
NO demand
ECO mode ON (illuminated)
Gain access to the PCB (use insulation mat as necessary)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Step 1:
Measure the voltage across pin 1 of ST17 and mains neutral. Expected voltage 13V DC. (A voltage of up to 30V DC may be measured initially but this should decrease and settle at approximately 13V DC)
Step 2:
Press and hold the reset button on the control panel for 2 seconds and then release, the voltage should then drop away and return to 13V DC.
Step 3:
Repeat Steps 1 and 2 at the following locations