Technical data

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7.10 EXTERNAL FAULTS
Before carrying out any fault-finding or component
replacement, ensure the fault is not attributable
to any aspect of the installation.
For example, external wiring fault, service valves
closed, gas supply turned off, etc. The table
below may assist in identifying some common
installation faults.
7.11 ELECTRICAL CHECKS
Any electrical checks must be carried out by a
suitably qualified person.
7.11.1 EARTH CONTINUITY TEST
Isolate the appliance from the electrical supply,
and using a suitable multi-meter carry out a
resistance test. Connect test leads between an
appliance earth point and the earth wire of the
appliance supply cable. The resistance should
be less than 1 ohm. If the resistance is greater
than 1 ohm check all earth wires and connectors
for continuity and integrity.
7.11.2 SHORT CIRCUIT CHECK
Isolate the appliance from the electrical supply,
and using a suitable multi-meter, carry out a short
circuit test between the Live & Neutral connections
at the appliance input board (fig.14).
Repeat above test on the Live & Earth connections
at the appliance input board (fig.14).
NOTE
Should it be found that a fuse has failed but no
fault is indicated, a detailed continuity
Check will be required to trace the fault. A visual
inspection of components may also assist in
locating the fault.
7.11.3 POLARITY CHECK
With the appliance connected to the electrical
supply and using a suitable multi-meter, carry out
the following voltage tests:
● connect test leads between the Live & Neutral
connections at the appliance input board (fig.14).
The meter should read approximately 230V ac.
If so proceed to next stage. If not, see section
7.11.4.
● connect test leads between the Live & Earth
connections at the appliance input board (fig.14)
the meter should read approximately 230V ac.
If so proceed to next stage. If not, see section
7.11.4.
● connect test leads between the Neutral & Earth
connections at the appliance input board (fig.14)
the meter should read approximately 0 – 15Vac.
If so polarity is correct. If not, see section
7.11.4.
7.11.4 REVERSED POLARITY OR SUPPLY FAULT
Repeat the above tests at the appliance isolator,
if testing reveals correct polarity and/or supply at
the isolator, re-check wiring and connections
between the isolator and the appliance.
If tests on the isolator also reveal reversed polarity
or a supply fault, consult the local electricity
supplier for advice.
7.11.5 RESISTANCE TO EARTH CHECK
Isolate the appliance from the electrical supply,
and using a suitable multi-meter carry out a
resistance test. Connect test leads between the
Live & Earth connections at the appliance input
board (fig.14). If the meter reads other than
infinity there is a fault that must be isolated, carry
out a detailed continuity check to identify the
location of the fault.
IMPORTANT
These series of checks must be carried out
before attempting any fault-finding procedures
on the appliance. On completion of any task that
required the disconnection and re-connection of
any electrical wiring or component, these checks
must be repeated.
7.11.6 FUSES
The appliance is equipped with spare fuses.
These fuses are located on the covers of the input
board and main PCB respectively. If a fuse has
blown it is usually indicative of an external wiring
fault or a faulty component such as the pump, fan,
valve actuator, etc. Under no circumstances
should a blown fuse be replaced with one of a
higher rating.
7.12 FAULT FINDING
BEFORE ATTEMPTING ANY FAULT
DIAGNOSIS OR REPAIR THE FOLLOWING
PROCEDURE SHOULD BE CARRIED OUT:
● carry out the relevant electrical checks as
detailed in section 7.11;
● disconnect any external wiring from plug M7
(terminals 2 & 3) and replace with a solid link
wire;
● ensure the appliance is protected – externally –
by a 3-amp fuse.
7.12.1 FAULT FINDING TESTS
If a lockout code is displayed on digits 3 & 4,
please refer to section 7.6 for the cause of the
lockout.
7.12.2 WIRING DIAGRAMS
Figures 33 & 34 indicate the positions of all plugs,
fuses and internal wiring configuration.
Fault code
displayed
E 02
b/E 18
E 36
Possible cause
Gas turned off
Air in gas pipe
Insufficient gas
Pump seized
Flow/return service valve closed
Flow sensor cable disconnected
FAULT
No display, boiler inactive
No display, pump running
No display, pump running, fan speed alternating
No display, boiler working OK
Pump failure
Fan fault
Ignition fault
GO TO
Test 1
Test 1A
Test 1A
Test 1A
Test 2
Test 3
Test 4