Viessmann VITODENS 200 WB2A, Installation & Servicing Instructions Manual

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a)
Gain access by removing the burner assembly as described in section 9.1,
steps (b) to (g).
b)
Separate the fan/gas valve assembly from the burner by removing the two
6mm socket head screws.
c)
Separate the fan from the venturi/gas valve assembly by removing the two
5mm screws taking care not to damage the gasket.
d)
Replace the fan and reassemble in reverse order.
e)
Finally, ensure that the outer casing is secured in position and carry out a
combustion check as in 5.6.
k)
Remove the siphon connecting pipe from the bottom of the heat exchanger
together with its bulkhead seal.
l)
Remove the retaining clips from the return connection of the heat exchanger
and above the lower right hand bulkhead and remove the return pipe.
m)
Support the flue system above the flue connection collar.
n)
Remove the screws and clamps retaining the flue connection collar and
remove the collar.
o)
Unscrew the automatic air vent from its sea behind the flue collar.p) Slacken
the four M6 nuts securing the heat exchanger rear brackets, slide the heat
exchanger upwards to release it from the keyhole slots and remove in a
forward direction.
q)
Replace the heat exchanger and assemble in reverse order ensuring that all
joints and seals are correctly made.
r)
Connect the filling loop, open the CH flow and return valves and re-pressurise
the system to design pressure using the filling loop valves and venting as
necessary. Check all connections for soundness, then disconnect the filling
loop. Finally, ensure that the outer casing is secured in position and carry out a
combustion check as in 5.4.
9 Replacement of Parts
9.1 Heat Exchanger
9.2 Fan Assembly
54