Benchmark i-mini 30 Installation And Servicing page 56

78 ALTERNATING '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.
79 ALTERNATING 'F' AND '4' - FLOW THERMISTOR FAuLT
Is the wiring securely connected to the Flow Thermistor
(located in the top of the Heat Exchanger?)
Disconnect the wiring from the Flow Thermistor
Check the resistance using a suitable multimeter connected
across the Thermistor's terminal pins.
At 25 C expect
o
At 60 C expect
o
At 85 C expect
o
Is the Thermistor value correct?
Is the wiring securely connected to the low voltage 6 way
connector at the front left hand side of the PCB?
80 AlteRnAtinG 'c' AND '2' - BCC FAuLT (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)
Replace the BCC with a new BCC (that is correct for the
boiler). After switching power on and 'c0' being shown,
press restart. Is 'c2' still shown?
ReStARt PRoCedURe - To restart boiler, turn mode knob to restart position and immediately turn knob back to required setting.
56
Fault Finding
YES
9,700 - 10,300 Ohms
2,400 - 2,600 Ohms
1,000 - 1,100 Ohms
YES
YES
NO
Securely connect the wiring to the Flow
Thermistor
NO
Fit a new Thermistor
NO
Securely connect the wiring to the PCB
Replace PCB
YES
NO Securely insert the correct BCC for the boiler
into the PCB and after switching power on and
'c0' being shown, restart boiler.
note. Ensure the correct orientation of BCC by
placing "TOP" side up.
YES
Replace PCB
i-mini -
Installation and Servicing