Benchmark Procombi Exclusive 24 Installation & Servicing Instructions Manual page 56

74 ALTERNATING 'F' AND '4' - FLOW THERMISTOR FAULT
Check the resistance using a suitable multimeter
connected across the thermistor's terminal pins.
o
At 25 C expect
At 60 o C expect
o
At 85 C expect
Is the Thermistor value correct?
75 ALTERNATING 'F' AND '5' - RETURN THERMISTOR FAULT
Check the resistance using a suitable multimeter
connected across the thermistor's terminal pins.
At 25 o C expect
o
At 60 C expect
o
At 85 C expect
Is the Thermistor value correct?
56
FAULT FINDING
9,700 - 10,300 Ohms
2,400 - 2,600 Ohms
1,000 - 1,100 Ohms
9,700 - 10,300 Ohms
2,400 - 2,600 Ohms
1,000 - 1,100 Ohms
NO
Fit a new Thermistor
YES
Is there continuity between the PCB and
the Thermistor?
NO
Check and replace
wiring as necessary
NO
Fit a new Thermistor
YES
Is there continuity between the PCB and
the Thermistor?
NO
Check and replace
wiring as necessary
Procombi Exclusive -
YES
Replace PCB
YES
Replace PCB
Installation and Servicing