44
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Service and spares
AU/NZ
6 720 646 195a (2010/11)
6.7
Cleaning the heat exchanger
B
Isolate the power to the boiler and remove outer case
and base panel.
1. Refer to figure 71 and remove the clip from gas valve
outlet.
2. Pull the gas outlet elbow free from the gas valve.
Fig. 71 Gas valve connection
B
Remove electrical connector and earth wire from fan.
B
Disconnect spark electrode and flame sensor
connections.
1. Refer to figure 72 and undo the securing nut on the
top of the heat exchanger and remove the retaining
plate assembly.
Fig. 72 Securing nut
1. Refer to figure 73 and rotate fan and air/gas manifold
assembly around the top of the heat exchanger until
it stops at the lug.
B
Lift up assembly and remove from boiler.
2. Remove the cover panel by removing retaining screw.
Fig. 73 Rotate air/gas manifold
NOTE:
Combustion testing
B
Combustion testing must be carried out
by an authorised person. Testing must
not be attempted unless the person
carrying out the combustion check is
equipped with a combustion analyser
and competent in its use.
NOTE:
CO/CO
2
checks
B
If the joint between the air/gas manifold
and heat exchanger is disturbed the
sealing gasket must be replaced .
After completing the service of the boiler,
the CO/CO
2
must be checked and set to
the limits shown in “setting the air/gas
ratio” on page 43.
There is an accessory kit available designed
for cleaning the heat exchanger, part
number: 7 716 192 312.
If the plastic elbow can not be easily
removed, undo the nut to push the plastic
elbow out of the fitting.
To prevent damage to the electrodes when
removing the air/gas manifold, disconnect
the leads to the electrodes.
1.
2.
6720643895-72.1Wo
1.
6720643895-60.1W
o
6720643895-63.1Wo
1.
2.