12
13
BASIC Control models:
8.9.4
Disconnect the following:
a.
Air circulation fan flying leads from the Fan assembly,
b.
230V mains ‘
L
’,
‘
N
’ and ‘
E
’ from connection block terminals ‘
1
’ and ‘
2
’, and
Earth stud
respectively,
c.
Room thermostat connections from connection block terminals ‘
7
’ and ‘
8
’,
d.
Limit switch from connection block terminals ‘
13
’ and
‘
14
’,
e.
Fan Delay Control from connection block terminals ‘
18
’ and
‘
17
’,
f.
Multifunctional Control from connection block terminals ‘
16
(N) ,‘
15
’ (L) and
Earth stud.
g.
Water heater from connection block terminals ‘
10
’ (L) and ‘
9
’ (N),
h.
Water Pump from connection block terminals ‘
12
’ (L) and ‘
11
’ (N),
i.
Cleanflow from connection block terminals ‘
19
’ (24V) and ‘
20
’ (0V),
j.
Earth lead from the fan chamber floor,
Both model types:
8.9.5
Release the hinge screw and withdraw the Electrical assembly, releasing wiring from cable clamps and grommets
as required.
8.9.6
Refitting or replacement is in reverse order.
8.10
ELECTRONIC MODULE REMOVAL (SYSTEM E-T models only)
8.10.1 Ensure that the electrical is isolated.
8.10.2 Remove the appliance front door, release the securing screw and hinge down the electrical panel.
8.10.3 Disconnect terminals ‘
21
’
to ‘
33
’ from the Electronic module.
8.10.4 Release the 2 x screws and nuts securing Electronic module to Electrical assembly and remove module.
8.10.5 Refitting or replacement is in reverse order.
8.11
TRANSFORMER REMOVAL (BASIC Control models only):
8.11.1 Ensure that the electrical is isolated.
8.11.2 Remove the appliance front door, release the securing screw and hinge down the electrical panel.
8.11.3 Disconnect the conductors from the large Transformer, noting their position for subsequent reconnection.
8.11.4 Release 2 x screws, nuts and star washers securing Transformer to the Electrical assembly, and remove the
Transformer.
8.11.5 Refitting or replacement is in reverse order.
8.12
TIME CONTROL and SWITCH REMOVAL:
8.12.1 Ensure that the electrical is isolated.
8.12.2 Remove the appliance front door, release the securing screw and hinge down the fan chamber door.
Time Control
removal:
8.12.3 Disconnect conductors ‘
C1
’, ‘
C2
’, ‘
C3
’ and ‘
C5
’ from the Time control.
8.12.4 Release the 3 x fixing screws, and withdraw the Time control.
8.12.5 Refitting or replacement is in reverse order.
8.12.6 Set Time Control to required ON and OFF times.
8.12.7 Set Time Control to correct time.
Switch removal:
8.12.8
Disconnect the conductors from the switch terminals.
8.12.9
Depress the retaining clips and press the switch out of the fascia panel.
8.12.10 Refitting or replacement is in reverse order.
WARNING: The fascia panel is held in place by push fit retainers which must be removed with caution to avoid
causing damage to the support pins. Removal of the fascia is not advised unless it is intended to be replaced.
8.13
FAN DELAY CONTROL/LIMIT SWITCH REMOVAL:
8.13.1 Ensure that the electrical supply is isolated.
8.13.2 Remove appliance front door, release the securing screw and hinge down the fan chamber door.
8.13.3 Disconnect the following at the Electrical panel:
a.
Limit switch from connection block terminals ‘
13
’ and
‘
14
’,
b.
Fan Delay Control from connection block terminals ‘
18
’ and
‘
17
’,
c.
Earth connection from common earth stud.
8.13.4 Release the 2 x 4mm screws securing the Limit switch mounting plate, and withdraw the control from the
appliance by drawing the conductors through the grommet in the fan chamber floor.
8.13.5 Refitting or replacement is in reverse order.
8.14
HEAT EXCHANGER ACCESS:
8.14.1 Ensure that the electrical supply is isolated.
8.14.2 Remove the appliance front door.
8.13.3 Remove the Fan Delay Control/Limit switch wiring loom clip from the return edge of the fan chamber floor.
8.13.4 Release the 6 screws securing the access plate to the bulkhead, and withdraw the access plate and gasket.
8.13.5 Release the 8 screws securing the top access cover plate, and withdraw the cover plate and gasket.
8.13.6 Reassembly is in reverse order.
NOTE: When reassembling, ensure that the gaskets are soundly sealed, and fully re-commission the heater.
9.
DEFECT DIAGNOSIS
9.1
IMPORTANT: If an electrical defect occurs after installation of the appliance; preliminary earth continuity,
polarity, and resistance to earth checks should be carried out with a multimeter. On completion of any
maintenance/fault-finding task that has required the breaking and remaking of electrical connections, then
checks of continuity, polarity, and resistance to earth must be repeated.
9.2
WARNINGS:
9.2.1
When purging or checking gas supplies, ensure that the ventilation to the room or cupboard is adequate, and that
all naked lights are extinguished.
9.2.2
SYSTEM E-T models:
a.
When carrying out any electrical testing, a test meter MUST be used, since low resistance test devices can
cause damage to the Electronics module.
b.
Before commencing defect diagnosis, ensure that the Thermista-stat is set to maximum, the mains supply
is ‘ON’ and the time control (if fitted) is at an ‘ON’ position.
c.
Care is to be taken during the replacement and handling of electronic assemblies (ie electronic panel,
airflow sensor or Thermista-stat), it is not practical to rectify defects on these assemblies, except at the
manufacturer, and any attempt to do so may render the guarantee or factory replacement arrangement
invalid.
SYMPTOM
POSSIBLE CAUSE
REMEDY
a.
Pilot will not light.
i. No gas supply to heater.
Check for gas at inlet pressure test
point on multifunctional control.
ii. Gas supply pipe not purged.
Purge gas supply pipe in accordance
with BS 6891.
iii Pilot orifice restricted.
Clear pilot orifice or replace pilot injector.
iv Piezo system faulty.
Check igniter, lead, and electrode.
v. Excessive gas supply pressure.
Check that mains gas pressure is 20mbar,
and reduce if necessary.
b.
Pilot lights but goes
i. Connection between thermo-
Check connection is secure.
out on releasing START
couple and Multifunctional
button during initial
control not secure.
light-up, or after
normal operation.
ii. Faulty Multifunctional
Replace Multifunctional control.
control.
iii. Faulty thermocouple.
Replace pilot assembly.
iv. Pilot orifice restricted.
Clear pilot orifice or replace pilot injector.
v. Air inlet/flue outlet fitted
Check that inlet/outlet arrangements conform
incorrectly.
to Fig. 3, and that seals are air tight.
c.
Main burner lights but
i. Loose electrical connection
Check connections.
fan fails to run after
on Fan Delay Control.
approximately 3 mins.
ii. Faulty Fan Assembly.
Replace, taking care to not damage impeller.
iii. Faulty Fan Delay Control.
Replace.
iv. Burner pressure setting incorrect.
Adjust.
