28
REPLACEMENT OF PARTS
9
Befor
e commencing any service operation, ISOLATE the mains
electrical supply and TURN OFF the gas supply at the main
service cock.
Replacement of most parts first requires the removal of the casing
panels and the combustion chamber lid; refer to section 6.2.
There may be some slight water spillage; so electrical components
should be protected.
It is the law that any service work must be carried out by a
registered person.
9.1
PRIMARY HEAT EXCHANGER
Inspect, and if ther
e are deposits of soot or dirt between the
blades of the heat exchanger clean using a soft brush or vacuum
cleaner, ensuring that the flame ports are not obstructed.
a)
Remove the primar
y heat exchanger as section 9.1.
b)
The fr
ont insulation may now be replaced, but to replace the
side and rear insulation, the burner must be removed. Refer to
section 6.3.
c)
Fit the new insulation and r
e-assemble in reverse order.
d)
Ensur
e that all joints and seals are correctly re-fitted and
recommission the system (if necessary) using the procedure in
section 5.1.
It is r
ecommended that a protective mask is worn
when changing or handling the insulation material.
9.2
COMBUSTION CHAMBER INSULATION
i)
Move the pipe N upwar
ds freeing it from the connection and
rotate towards right.
j)
Remove the heat exchanger by sliding it for
wards.
k)
Reassemble the boiler car
rying out the removal operations in
reverse order.
Fit the clip
I
with the ar
row pointing
upwards as illustrated in Fig. 34.
IMPORTANT - Do not force the connection G when
tightening it.
Cleaning
Inspect, and if ther
e are deposits of soot or dirt between the
blades of the heat exchanger clean using a soft brush or vacuum
cleaner, ensuring that the flame ports are not obstructed.
Note:
Do not use a wir
e brush or any abrasive material and
avoid any damage to the protective varnish with which the
exchanger has been covered.
g)
Loosen the connection K and move the pipe L downwar
ds
freeing it from the connection of the primary heat exchanger.
h)
Remove the clip M.
Refer to Figur
e 34
a)
Remove the casing panels and the combustion chamber lid
(see section 6.2).
b)
Empty the primar
y circuit of the boiler.
c)
Remove the combustion chamber fr
ont C by unscrewing the
screws A and removing the fan bracket B (Fig. 34).
d)
Remove the scr
ews D and the baffle E.
e)
Loosen the connection G and slightly move the pipe H
upwards.
f)
Remove the clip I and the safety ther
mostat J. It is not
necessary to disconnect it from the wiring.
W
arning: After cleaning or replacement, if it
is deemed necessary to undertake a
combustion analysis, refer to section 6.1.
!
Refer to Figur
e 35
a)
Remove the casing panels and the combustion chamber lid
(see section 6.2).
b)
Empty the primar
y circuit of the boiler.
c)
Remove the fan O and the air pr
essure switch P.
d)
Remove the flue temperatur
e probe NTC Q.
e)
Completely loosen the connection G and slightly move the
pipe H upwards.
f)
Remove the clip R and move the pipe S downwar
ds freeing it
from the connection, then turn it towards the right.
g)
Using pliers, r
emove the spring T moving it downwards and
disconnect the rubber pipe U.
9.3
CONDENSING HEAT EXCHANGER
34
