RESISTANCE THERMISTOR AND HARNESS DHW

Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4

Set Multimeter to Resistance

Remove connector X6 from the PCB

Measurement:

Measure the resistance between the blue wires (pins 5 and 6) on connector X6.

fr optimax he plus 38 c con x5 off pcb.gif

Note:
It can be difficult to test on these connectors, ensure a good connection is made, often it can be easier to test on the metal strip on the side of the connector.

Note: Clicking on the resistance table will switch between table and graph view.

Resistances vary with temperature and should conform approximately to the table below:

Temperature Range (°C)	Resistance Range
0°C to 10°C	19.0kΩ - 30.0kΩ
10°C to 20°C	12.0kΩ - 19.0kΩ
20°C to 30°C	8.2kΩ - 12.0kΩ
30°C to 40°C	5.6kΩ - 8.2kΩ
40°C to 50°C	3.9kΩ - 5.6kΩ
50°C to 60°C	2.8kΩ - 3.9kΩ
60°C to 70°C	2.0kΩ - 2.8kΩ
70°C to 80°C	1.5kΩ - 2.0kΩ
80°C to 90°C	1.2kΩ - 1.5kΩ
90°C to 100°C	900Ω - 1.2kΩ