20
Fig. 23
A
C
D
A
B
E
C
D
Fig. 22
Fig. 20
A
B
note of all wiring connections and jumper tag configuration,
disconnect all wiring from the PCB, locate and remove
the PCB securing screws, remove the required PCB.
Replace in the reverse order ensuring that the position of
the 3 control knobs are correctly aligned with the respective
potentiometers on the PCB.
Ensure that the correct jumper tag configuration has been
respected. It will be necessary to check the functioning of
the PCB is set for the correct boiler type/application.
6.9 GAS VALVE (fig. 21)
Carry out component removal procedure as described in
6.4. The gas valve must be changed as complete unit.
Disconnect the electrical plug and leads from the gas valve,
slacken and unscrew gas valve inlet
and outlet
connections.
Please note,
the sealing washers
(B)
must
be discarded and replaced with new sealing washers.
Disconnect the compensation pipe
(C)
. Locate and remove
gas valve retaining screws
(D)
on the underside of the
boiler if required, the gas valve can now be removed.
Replace in the reverse order. Check and adjust burner
pressure settings.
WARNING, A GAS SOUNDNESS CHECK MUST BE
CARRIED OUT.
6.10 INJECTOR (fig. 21)
Carry out component removal procedure as described in
6.4. Unscrew and remove gas pipe connections
(A & E)
.
Locate and remove the injector
(F)
inside the pipe. Replace
in the reverse order. Check and adjust burner pressure
settings.
WARNING, A GAS SOUNDNESS CHECK MUST BE
CARRIED OUT.
6.11 ELECTRODES & CONDENSE SENSOR (fig. 22)
Carry out component removal procedure as described in
6.4. Unclip and remove the air chamber front and RH side
covers. Disconnect the electrode leads and ancillary
wiring from their respective connectors. Remove the
retaining screws
(A)
for electrode
and remove. Remove the
retaining nut
(C)
for condense sensor
(D)
and remove.
6.12 FLUE FAN & MIXER (fig. 23)
Carry out component removal procedure as described in
6.4. Unclip and remove the air chamber front and the RH
side covers. Slacken the gas pipe
(A)
at the air box
connection and swing/rotate away from the fan assembly.
Locate and remove the sense electrode. To remove the
mixer
(B)
locate and remove the three screws
(C)
. To
remove the fan
(D)
, disconnect the electrical connections
attached to the fan, locate and remove the four screws
(E)
. Gently ease the fan from its location. Replace in the
reverse order. Ensure all seals are in good condition, taking
care to ensure they are replaced correctly.
6.13 BURNER (fig. 24)
Carry out component removal procedure as described in
6.4. Unclip and remove the air chamber front and the RH
side covers. Slacken the gas pipe
(A)
at the air box
connection and swing/rotate of the fan assembly. Locate
and remove the 3 internal nuts
(B)
which secure the fan
assembly in position
(C)
to the heat exchanger
(D)
. Gently
ease the fan assembly out of its location. Once the
assembly has been removed, the burner
(E)
can be
withdrawn from the heat engine. Ensure the seal
(F)
is in
good condition, taking care to ensure it is replaced
correctly. Replace in the reverse order.
Fig. 21
A
E
F
B
B
C
D