Maintenance
4
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 11S/19S/24S/24C • 02/2006
33
Subject to modifications resulting from technical improvements!
Buderus • http://www.buderus-domestic.co.uk
4.1.2
Cleaning the heat exchanger after dismantling
z
Disconnect the system from the power supply.
z
Close the gas shutoff valve.
z
Loosen the retaining screw and remove the casing.
z
Close the heating shutoff valves and drain the system.
z
Open snap closures and remove combustion-chamber
cover.
z
Release plug-in connection of fan power lead (fig. 40,
item 1), burner-control unit fan control lead (fig. 40, item 2)
and gas-burner assembly (fig. 40, item 3).
z
Loosen union nut on gas valve assembly (fig. 40, item 4).
z
Push safety plate out of way.
z
Turn air suction tube and pull off from below.
z
Swivel the air combination unit forward (fig. 41, item 1).
z
Pull the air combination unit up and out of bayonet
connector (fig. 41, item 2) and remove via front of unit.
z
Remove burner gasket (fig. 42, item 1) and rubber seal in
combustion chamber from top (fig. 42, item 2).
z
Remove burner by pulling upwards through the opening
(fig. 47, item 1) and release the four retaining clips (fig. 47,
item 2).
z
Remove the front casing shell of the combustion chamber.
z
Remove the hot surface ignitor (fig. 44, item 1) and
ionisation electrode (fig. 44, item 2).
In the case of the hot surface ignitor:
Loosen the fixing screw of the hot surface ignitor, detach
both earth (ground) leads and remove the retaining plate of
the hot surface ignitor by pulling it upwards, withdraw the
hot surface ignitor by pulling it upwards.
In the case of the ionisation electrode:
Swivel the retaining plate to one side and carefully remove
the ionisation electrode by pulling it upwards.
Fig. 45 Draining the system
Drain
temporary
hose
Stop
valve
Stop
valve
DHW Cold
(combi only)
CH Flo
w
CH Retur
n
CAUTION
Cut hot water on supply side by closing the
heating shutoff valve.
CAUTION
Drain the system via the temporary filling loop
(fig. 45) or the screw-in drain plug (fig. 46,
item 1) located under the pump.
Fig. 46 Screw-in drain plug
1
Fig. 47 Remove burner and release retaining clips
1
2
