Halstead Eden CBX, Installation And Servicing Instructions

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30
FAULT FINDING
8
8.1
GENERAL
Before looking for a fault condition, check that:
G
The mains electrical supply is turned on.
G The clock, room or cylinder/tank thermostat (where fitted) are
calling for heat.
G
The gas service cock is open.
G The CH and DHW isolation cocks are open.
G
The system is at design pressure.
Before attempting any electrical fault finding, always conduct the
preliminary electrical system checks as described in the Instructions
for the British Gas Multimeter, or other similar instrument.
On completion of any service or fault finding operation involving
making or breaking electrical connections, always check for
EARTH CONTINUITY, POLARITY and RESISTANCE TO EARTH.
Detailed procedures for replacing faulty components are described
in section 9 (Parts Replacement).
8.2
DIAGNOSTIC LED INDICATORS
FASCIA PANEL, Figure 30
The Reset LED shows steady RED in a lockout condition and the
error code will be displayed by the 4 yellow lights above the two
control knobs.
For fault finding, refer to the diagnostic chart shown below,
together with the notes given in sections 8.3, 8.4 and 8.5.
Depending on the fault condition, the boiler can be reset by
pressing the RED
Reset light.
8.3 FAULT FINDING CODES
In the event of the appliance failing to light, refer to the
Diagnostics Chart.
LED 1
•
•
• •
CLOCK
•
PRESSURE
GAUGE
•
DHW TEMP
CONTROL
•
CH TEMP
CONTROL
•
ON/OFF
SWITCH
•
LED 3 LED 2 LED 4
•
RESET & burner/
lock-out LED
FACIA PANEL
30
When the hot water tap is turned on, the control should perform a
series of checks followed by an ignition sequence.
Refer to section 5.2.
If the control has powered up correctly but does not respond to a
DHW demand, check the following:
a) Check that the DHW flow rate at the tap is greater than 2.5
litre/minute.
b) Check the operation of the DHW flow turbine, Figure 28.
c) Check the wires to the DHW flow turbine.
d) Check connector X8 is correctly connected to the PCB.
If the above items are ok, replace the PCB.
If DHW temperature fluctuates heavily during a long draw off,
check the secondary plate heat exchanger filter for debris, clean
and replace, (refer to section 9.19).
FINDING (CBX APPLIANCES ONLY)
8.4
DOMESTIC HOT WATER FAULT
Upon a demand for Central Heating, (closure of the time switch and
room thermostat, where fitted), the controls should carry out a set of
start up checks, followed by an ignition sequence. Refer to Section 5.2.
If the control has powered up correctly but does not respond to a CH
demand. Check voltage between pin 2 connector X1A (orange wire)
and pin 2 connector X1B (blue wire). If 0 V ac, check room thermostat
and clock. If 230 V ac, check control for lockout or blocking codes,
(refer to section 8.3), check operation of the pump.
Note: Whenever a CH demand is removed, either by the timer, the
room thermostat or by the appliance's internal temperature control, an
anti cycle mode is initiated which prevents the appliance from firing in
CH mode for 5 minutes. Ensure that the control is not in this mode by
removing power from the control and restoring it after a delay of 10
seconds.
If room thermostat and clock are OK and no lockout or blocking code
exists and the control is not in anti cycle mode, then
replace PCB.
8.5
CENTRAL HEATING FAULT FINDING
For further information contact: Halstead Boilers Ltd. Service Help
line: 08450 710780.