page no. 47 of 68
CPx Range Users, Installation & Servicing Instructions Doc Ref M201 issue 2.9 Nov 2018.
Fault
Action
Heater does not turn on
1. Check electrical supply is ON.
2. Check controls are ON or calling for heat.
3. Faulty burner control unit.
4. Limit thermostat open circuit/faulty, interlock relay not set/faulty.
5. Check fuel supply is present.
Heater goes into high limit trip
1. Faulty or incorrect setting fan thermostat - See Section 2.6.6
2. Faulty or incorrect setting limit thermostat - See Section 2.6.6
3. Faulty fan assembly - change.
4. Fan motor out on thermal overload/inbuilt motor thermal trip.
- check running amps. See section 1.2
- check duct resistance. See duties, page 7
- check that airflow through the heater is not restricted.
Main fan runs continuously
1. White button on fan/limit thermostat pushed in - pull out.
2. Summer/Winter switch set to Summer - set to Winter.
3. Faulty or incorrect setting fan thermostat - See Section 2.6.6
Main fan fails to run
1. Fan motor or capacitor failed - replace.
2. Fan thermostat faulty - replace.
3. Fan contactor failed - replace (3ph units)
4. Reset Motor Overload
Indication of operation
In normal operation, the various statues are indicated in
the form of colour codes according to the table below.
Diagnosis of fault causes
After lock-out has occurred, the red signal lamp is steady
on.
The control box has a diagnostic function that can identify
the likely causes of any malfunctions (indicator: RED LED).
In order to be able to use this function, press and hold
the reset button for at least 3 seconds from when the
appliance is made safe (lock-out).
The control box sends a sequence of pulses that are
repeated at 2-second intervals.
Blink code
Possible cause of fault
2 blinks
No flame at the end of safety time:
faulty or soiled gas valves.
faulty ionisation probe.
poor adjustment of burner, no gas.
faulty ignition transformer.
neutral / phase exchange.
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3 blinks
Air pressure switch does not close or is
already closed before heat demand:
faulty air pressure switch.
air pressure switch incorrectly regulated.
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4 blinks
Presence of flame (light) in chamber:
in stand-by position.
with thermostat of heat demand in idle
or working position.
during
pre-purge.
during
post-purge.
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6 blinks
Loss of air pressure:
during
pre-purge.
during or after safety time.
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7 blinks
Loss of flame during operations after 3
attempts of re-cycle:
faulty or soiled gas valves.
faulty ionisation probe.
short circuit between ionisation probe
and earth of the burner.
poor adjustment of burner, no fuel
To reset the control box after the diagnostics display, press
the lockout-reset button.
