54
FaULT FINDINg
F
aUL
T
F
INDINg
F
aUL
T
F
INDINg
F
aUL
T
F
INDINg
F
aUL
T
F
INDINg
F
aUL
T
F
INDINg
Indep Combi -
Installation and Servicing
80 aLTERNa TINg ‘F’ aND ‘4’ - FLOW ThERMIsTOR FaULT
Disconnect the wiring from the Flow Thermistor
Check the resistance using a suitable multimeter connected
across the Thermistor’s terminal pins.
At 25
o
C expect
9,700 - 10,300
Ohms
At 60
o
C expect
2,400 - 2,600
Ohms
At 85
o
C expect
1,000 - 1,100
Ohms
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 top of the Heat Exchanger?)
YES
NO
Securely connect the wiring to the Flow
Thermistor
NO
79 aLTERNa TINg ‘F’ aND ‘9’ - pCB FaULT
Replace PCB -
Ensure that the BCC (boiler chip card - small plastic part) is
fitted to the PCB otherwise replace PCB.
81 aLTERNa TINg ‘ c’ aND ‘2’ - BCC F aULT (BOILER ChIp CaRD)
Is the correct BCC for the boiler securely inserted into the
slot at the front left of the PCB?
(identified by the label on the BCC)
YES
NO
Securely insert the correct BCC for the boiler
into the PCB and after switching power on and
‘c0’ being shown, reset boiler.
Note. Ensure the correct orientation of BCC by
placing “TOP” side up.
Replace the BCC with a new BCC (that is correct for the
boiler). After switching power on and ‘c0’ being shown,
press reset. Is ‘c2’ still shown?
Replace PCB
YES
REsET pROCEDURE - To reset boiler, turn mode knob to reset position and immediately turn knob back to required setting.
