33
A
B
D
E
F
I
J
N
M
I2
J2
O
P
7.3 REPLACEMENT OF COMPONENTS
Although it is anticipated that this appliance will give years of
reliable, trouble free service, the life span of components will be
determined by factors such as operating conditions and usage.
Should the appliance develop a fault, the fault finding section
will assist in determining which component is malfunctioning.
7.4 COMPONENT REMOVAL PROCEDURE
To remove a component, access to the interior of the appliance
is essential. Isolate the appliance from the electrical supply and
remove the fuse. And when necessary, close all service valves
on the appliance, remove the appliance casing as described
in section 4.5 and drain the water content from the appliance
via the drain valve. Ensure some water absorbent cloths are
available to catch any residual water that may drip from the
appliance or removed component. Undertake a complete com-
missioning check as detailed in section 6, after replacing any
component.
ALWAYS TEST FOR GAS TIGHTNESS IF ANY
GAS CARRYING COMPONENTS HAVE BEEN
REMOVED
OR DISTURBED.
7.5 FRONT COVER REMOVAL
(FIG. 30)
Locate the 4 screws and remove the front cover.
7.6 PUMP ASSEMBLY
(FIG. 31)
Carry out component removal procedure as described in 7.4.
Disconnect and remove the pump outlet pipe (
A
) from the pump
assembly/combustion chamber connection.
Remove the expansion pipe locking pin (
B
) from the top of the
pump assembly and withdraw the flexible pipe. Disconnect the
electrical wiring from the pump’s electrical connection point (
D
).
Locate and remove the 2 securing screws (
E
) at the rear of the
pump assembly. Remove locking pin (
F
) from pump base and
lift pump assembly clear of the hydraulic manifold. The pump
assembly can now be removed from the appliance. Replace
carefully in the reverse order.
7.7 SAFETY VALVE
(FIG. 32)
Carry out component removal procedure as described in 7.4.
Disconnect the outlet pipe (
H
) from the safety valve, remove
safety valve locking pin (
G
) from the hydraulic manifold. Replace
in the reverse order.
7.8 LOWER AUTOMATIC AIR RELEASE
VALVE
(FIG. 31)
Carry out component removal procedure as described in 7.4.
Remove the expansion pipe locking pin (
B
) from the pump as-
sembly and remove the expansion pipe. Locate and remove
the AAV locking pin (
I
) from the pump assembly and remove
the AAV assembly (
J
). Replace in the reverse order.
7.9 WATER PRESSURE TRANSDUCER
(FIG.
33)
Carry out component removal procedure as described in 7.4.
Locate and remove the locking pin (
M
) from the water pres-
sure transducer (
N
). Remove the wiring. Carefully withdraw the
transducer. Replace in the reverse order.
7.10 FLOW THERMISTOR
(FIG. 4 - POS. 21)
Carry out component removal procedure as described in 7.4.
Unclip and remove the air chamber front cover. Unclip the flow
thermistor from the flow outlet pipe. Disconnect thermistor
electrical plug. Replace in the reverse order.
7.11 RETURN THERMISTOR
(FIG. 4 - POS. 23)
Carry out component removal procedure as described in 7.4.
Unclip the return thermistor from the return inlet pipe. Discon-
nect thermistor electrical plug. Replace in the reverse order.
7.12 PRINTED CIRCUIT BOARD
(FIG. 34)
Carry out component removal procedure as described in 7.4.
Pull the control fascia forward and lower it. Push the clips (
O
)
which secure the PCB cover, remove cover, after carefully tak-
ing note of all wiring connections and jumper tag configuration.
Unhook and remove connection block (
P
). Disconnect all wiring
H
G
Fig. 30
Fig. 31
Fig. 32
Fig. 33
Fig. 34