RESISTANCE THERMISTOR FLOW AND HARNESS

Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4

Set Multimeter to Resistance

Remove connector X9 from the PCB

Measurement:

Measure for resistance across pins 1 & 2 (red leads) of connector X9.
The resistance will vary according to the boiler temperature but should conform approximately to the table below:

Temperature Range (°C)	Resistance Range
0°C to 10°C	19.0kΩ - 29.0kΩ
10°C to 20°C	12.0kΩ - 19.0kΩ
20°C to 30°C	8.2kΩ - 12.0kΩ
30°C to 40°C	5.7kΩ - 8.2kΩ
40°C to 50°C	4.0kΩ - 5.7kΩ
50°C to 60°C	2.9kΩ - 4.0kΩ
60°C to 70°C	2.1kΩ - 2.9kΩ
70°C to 80°C	1.6kΩ - 2.1kΩ
80°C to 90°C	1.2kΩ - 1.6kΩ
90°C to 100°C	900Ω - 1.2kΩ

Note:
Click on resistance table to switch between table and graph view.