56
Installation and Servicing
Section 4 - Fault Finding
FAULT FINDING
4.7 ‘F 03’ - FAN FAULT
Does the wiring from the Fan to the PCB have
secure connections at both ends and has not
deteriorated? Does the wiring have continuity?
YES
Rectify Wiring &
connections
Is there 230 VAC at the Blue and Brown connections
to the 3 way connection on the Fan?
NO
Replace PCB
Replace Fan
NO
YES
4.8 F 04 OR L 04’ - FLOW THERMISTOR FAULT
Disconnect the wiring from the Flow Thermistor
Check the resistance using a suitable multimeter connected
across the Thermistor’s terminal pins.
Is the Thermistor value correct?
YES
Is the wiring securely connected to the low voltage 6 way
connector at the front left hand side of the PCB?
YES
Replace PCB
Fit a new Thermistor
NO
Securely connect the wiring to the PCB
Is the wiring securely connected to the Flow Thermistor
Located in the Flow Pipe lower LHS of Boiler
YES
NO
Securely connect the wiring to the Flow
Thermistor
NO
Temperature Resistance kΩ
25
o
C 9.7 – 10.3
60
o
C 2.4 – 2.6
85
o
C 1.0 – 1.1
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