Cleaning The Heat Exchanger - Worcester GREENSTAR 24i Junior Installation Instructions Manual

SERVICE AND SPARES
6.7

CLEANING THE HEAT EXCHANGER

NOTICE: COMBUSTION TESTING
B Combustion testing must be carried out
by a competent person. Testing must not
be attempted unless the person carrying
out the combustion check is equipped
with a Combustion Analyser conforming
to BS 7927 and is competent in its use.
NOTICE: CO/CO
B If the joint between the Air/Gas manifold
and heat exchanger is disturbed the
sealing gasket must be replaced.
B After completing the service of the
appliance, the CO/CO
and set to the limits shown in "Setting
the air/gas ratio" on page 47.
There is a special accessory kit available
specifically designed for cleaning the heat
exchanger. If required order 7 716 192 312.
B Isolate the power to the appliance and remove outer
case and base panel.
1. Refer to figure 78 and remove the clip from gas valve
outlet.
If the plastic elbow can not be easily
removed, undo the nut to push the plastic
elbow out of the fitting.
2. Pull the gas outlet elbow free from the gas valve.
2.
Fig. 78 Gas valve connection
B Remove electrical connector and earth wire from fan.
To prevent damage to the electrodes when
removing the air/gas manifold, disconnect
the leads to the electrodes.
B Disconnect spark electrode and flame sensor
connections.
48
CHECKS
2
must be checked
2
1.
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1. Refer to figure 79 and undo the securing nut on the
top of the heat exchanger and remove the retaining
plate assembly.
Fig. 79 Securing nut
1. Refer to figure 80 and rotate fan and air/gas manifold
assembly around the top of the heat exchanger until
it stops at the lug.
2. Remove the cover panel by removing retaining screw.
B Lift up assembly and remove from boiler.
1.
Fig. 80 Rotate air/gas manifold
6 720 644 741a (2010/10)
1.
2.
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