H 2 (Return Temperature Sensor); H 3 (Dhw Temperature Sensor) - IDEAL istor HE260 Installation And Servicing

102 H.....2..... (RETURN TEMPERATURE SENSOR)
Remove the boiler return
thermistor from the CH
return pipe.
Replace PCB
103 H.....3..... (DHW TEMPERATURE SENSOR)
Remove the boiler DHW
thermistor from the DHW
cylinder and disconnect
thermistor wires.
Replace PCB
68
FAULT FINDING
Check resistance. The sensors can be checked by
measuring their resistance, using a suitable multimeter
connected across the sensors' terminal pins
o
At 25 C expect 9,700-10,300
o
At 60 C expect 2,400-2,600
o
At 85 C expect 1,000-1,100
Are the thermistor values correct ?
YES
Is there continuity between the PCB
and the thermistor ?
Check resistance. The sensors can be checked by
measuring their resistance, using a suitable multimeter
connected across the sensors' terminal pins
o
At 25 C expect 9,700-10,300
o
At 60 C expect 2,400-2,600
o
At 85 C expect 1,000-1,100
Are the thermistor values correct ?
YES
Is there continuity between the PCB and
the thermistor ?
Ohms
Ohms
Ohms
NO
YES
NO
Ohms
Ohms
Ohms
NO
YES
NO
istor system store -
Replace the thermistor
Check and replace wiring
as necessary
Replace the thermistor
Check and replace wiring
as necessary
Installation and Servicing