52
Installation and Servicing
Section 4 - Fault Finding
FAUL
T FINDING
4.9 ‘F 05 OR L 05’ - RETURN THERMISTOR FAULT
Pump Housing
Check the resistance using a suitable multimeter
connected across the thermistor’s terminal pins.
Temperature
Resistance kΩ
25
o
C
9.7 – 10.3
60
o
C
2.4 – 2.6
85
o
C
1.0 – 1.1
Is the Thermistor value correct?
YES
Is there continuity between the PCB and the Thermistor?
YES
Replace PCB
Fit a new Thermistor
NO
Check and replace wiring as necessary
NO
4.10 ‘F 06’ - OUTSIDE SENSOR FAULT
Disconnect the wires to the outside sensor.
Check the resistance using a suitable multimeter
connected across the outside sensor’s terminal pins.
Temperature
Resistance kΩ
0
o
C
31.0 – 35.0
15
o
C
15.0 – 16.5
30
o
C
7.7 – 8.5
Is the Outside Sensor value correct?
YES
YES
Is the wiring securely connected between the
incoming terminal block boiler connection of the
Outside Sensor and the PCB?
Replace PCB
Fit a new Outside Sensor
NO
Securely connect the wiring at the
Terminal Block and the PCB
Is the wiring securely connected at both the boiler and
Outside Sensor?
YES
NO
Securely connect the wiring at both the
boiler and Outside Sensor
NO
Refer to Section
3.11