Heat Exchanger - Worcester 27i System Compact Installation, Commissioning And Servicing Instructions

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Fig. 99 Burner and gasket
TIGHTENING DOWN THE BURNER HOUSING
1. Tighten the burner housing castellated nuts [1] down gradually and
evenly and in a rotating sequence.
2. Tighten the castellated nuts down until they "bottom out" on the heat
cell, as indicated by the arrow on the figure below.
▶ Fit the spring clip [2] to secure the castellated nuts, if the hole does
not line up with a space, back the nut off slightly until the hole does
align with the slot.
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Fig. 100 Castellated nuts
[1] Castellated nut
[2] Spring clip
[3] Washer
[4] Burner housing bolts
[5] Tension springs
Greenstar i System Compact - 6 720 807 726 (2013/05)
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6720646610-74.1Wo
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6.8.14 HEAT EXCHANGER

Before removal:
▶ Isolate the electrical power to the boiler.
▶ Drain the system.
HEAT EXCHANGER DISCONNECTION
1. Undo the flow and return connections.
2. Pull both the flow and return pipes away from the heat exchanger.
▶ Replace the fibre washers (1) when replacing the heat exchanger.
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Fig. 101 Heat exchanger disconnection
HEAT EXCHANGER REMOVAL
▶ Ensure any electrical wires or connectors are removed.
▶ Remove the Auto air vent ( refer to section 6.8.7) to ease removal of
the heat exchanger
1. Unscrew the heat exchanger retaining nut.
2. Remove the heat exchanger retaining nut.
3. Remove the two screws securing the heat exchanger to the air box.
4. Lift the heat exchanger until the lower connection clears the hole in
the air box.
5. Pull the heat exchanger towards you to remove.
CAUTION: Component replacement:
▶ After replacement of a gas related component, where
a gasket or seal has been disturbed or replaced, check
for gas tightness using a gas sniffer/analyser.
▶ Also after re-assembly, carry out the following
checks:
Fan pressure in section 6.5,
Flue gas analysis in section 6.6,
▶ Re-assemble in the reverse order.
SERVICE AND SPARES
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