Buderus 500 - 24/C, Servicing Manual

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We reserve the right to make technical modifications Buderus Ltd. • http://www.buderus-domestic.co.uk
Servicing manual Gas condensing boiler Buderus 500-24/S, 500-24/C and 500-28/C • Issued 02/2006 45
box 85 Check the non return valve
z
Remove the fan, see box 76 to box 79.
z
Check to see if the non return valve (item 5 and 6, if fitted)
is soiled or defective.
z Loosen the upper nut (item 2).
z Loosen the two lower nuts (item 1).
z Turn the securing plate 180° counterclockwise (item 3).
z Remove the fan part (item 7).
z Bend the silicon seal (item 4).
z Remove the plastic valvehousing (item 5).
z Check the silicon valve (item 6) and replace when
necessary.
z After checking, refit all components in reverse order.
Make sure that the cam (item A) of the silicon valve is
mounted in the correct manner (A).
z First tighten the upper nut (item 2), then tighten the lower
two nuts (item 1).
z Refit all other components in reverse order, then put the
boiler into service, see box 51, 54 or 55.
box 86 Check the Venturi
z Take the boiler out of operation, see box 43, 44 or 47.
z Remove the air intake duct, see box 77.
z Remove the Venturi, see box 81, item 1.
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2
3
4
5
6
A
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box 87
z Check the article number of the Venturi against those
listed in the table in box 5.
z Check to ensure that the correct Venturi has been fitted.
This is done by comparing the article numbers listed
against the number on the Venturi (item 1), see box 5.
z Check the Venturi for soiling.
box 88
z Refit the Venturi and fan by following the above procedure
in reverse order.
z
Refit the air silencer tube.
z
Refit the casing and place the boiler into operation,
see box 51, 53, 54 or 55.
box 89 Check the pump – mechanical restrictions
z Remove casing, see box 47.
z Remove the vent screw on the front of the pump,
see box 57.
A
CAUTION!
Note that water will squirt out when the vent screw is
removed. Have a bucket and a supply of dry cloths to
hand.
box 90
z
Put the electrical system of the boiler into operation,
see box 54 and 55.
z Check to see if the pump is running. The pump may
become mechanically blocked if the heating system has
been out of use for an extended period.
z Insert a screwdriver and attempt to make the pump turn.
Use the screwdriver to turn the fan wheel in the direction
of rotation shown on the identification plate of the pump.
z Refit the vent screw to the pump.
z Fit casing, see box 51.
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