Fig. 42
32
7.2.7
Inspect the secondary condensate
heat exchanger. Deposits can be
cleared by removing and flushing out
the exchanger. Inspect the siphonic
condensate trap for a blockage. Any
deposits should be flushed out (fig. 55).
7.2.8
To remove condensate trap (sect. 5.4). Pull
forward the trap (fig. 55).
Unscrew the earth wire, and the sensor.
Replace in reverse order.
7.2.9
Examine the fan for any mechanical
damage, check to ensure free running of
the fan wheel. Clean the wheel if necessary
with a soft brush. Check sealing gasket and
renew if damaged.
7.2.10
Examine flue duct and flue hood and ensure
that there is no obstruction. Examine the
gasket at the entry into the flue duct.
7.2.11
It is essential that a good seal is made at the
outlet to the fan, renew this gasket if there is
any sign of damage or deterioration.
7.3
TO REMOVE/REPLACE THE CASING.
7.3.1
Remove the 2 screws that secure the upper
part and the 4 screws that fasten the lower
grating on the casing.
Carefully slide the casing forward to lift off.
7.4
TO REMOVE/REPLACE THE
COMBUSTION CHAMBER COVER
7.4.1
Remove the front casing panel (sect. 7.3).
7.4.2
Unscrew all the screws that fasten the cover
to the chamber body and put them into a
container so that they don’t get lost.
7.4.3
Detach the cover, being careful not to
damage the seal.
7.4.4
Reassemble in reverse order.
Ensure good seal of cover when replacing.
7.5
TO REMOVE/REPLACE THE FAN
ASSEMBLY (fig. 42).
7.5.1
Remove front casing (sect. 7.3).
Remove combustion chamber front cover
(sect. 7.4).
7.5.2
Disconnect the electrical connections from
the fan motor.
7.5.3
Support the fan and remove the two fixing
screws and bracket from the front of the flue
hood. Carefully withdraw from condensing
heat.
exchanger then from the appliance.
Place in a safe place until required
Reassemble in reverse order. Ensure wires
are connected correctly.
7.6 TO
REMOVE/REPLACE
CONDENSING
HEAT EXCHANGER (fig. 43).
Remove front casing (sect. 7.3).
Remove combustion chamber front cover
as in (sect 7.4).
7.6.2
Close the ON/OFF valves for the heating.
Drain the heating system.
7.6.3
Remove the fan.
7.6.4
Disconnect 4 unions for the heating water
pipelines and remove the two short pipes.
7.6.5
Remove screw holding the heat exchanger
to chamber. Disconnect condensing
discharge pipe by pulling off the pushfit
connector at top rear of boiler.
7.6.6
Pull the heat exchanger down and slightly
forward until it comes out of the connection
from chamber.
7.6.7
Replace in reverse order. Taking care to
refit discharge pipe at rear.
IMPORTANT:
When replacing heat
exchanger new seals must be used.
Summary of Contents for 780 Series
Page 2: ......
Page 7: ...7 Fig 3 OVERALL DIMENSION ...
Page 34: ...34 Fig 45 Fig 44 Fig 46 ...
Page 36: ...36 Fig 48 Fig 47 Fig 49 Fig 50 Fig 51 ...
Page 42: ...Fig 59 42 SECTION 9 ELECTRICAL SYSTEM DIAGRAM ...
Page 46: ...79 83 105 46 50 27 16 39 17 2 22 100 1 4 5 11 8 SECTION 11 ...
Page 49: ...49 ...
Page 50: ...COD 0017LIB06010 2 03 2010 ...
