
Supplied By www.heating spares.co Tel. 0161 620 6677
43
221473B
Diagram 4.21
Diagram 4.22
4593
2284
4 Replacement of Parts
PUMP
ADJUSTER
END
SCREW
PUMP
SPINDLE
TERMINAL
COVER SCREW
UPPER
PUMP
UNION
LOWER
PUMP
UNION
LOCATION
SLOT
CAP
UNION (4)
FLOW
DIRECTION
ARROW
SEALING
WASHER
AUTOMATIC
AIR VENT
4.24 Pump
Release the water pressure and drain the central heating circuit
of the boiler, refer to Section 1.3 and 1.6.
Remove control housing, refer to Section 4.11.
Disconnect the electrical connectors at the water pressure
microswitch. Remove the water pressure switch, refer to
Section 4.9.
Remove the terminal cover from the pump and disconnect the
cable, see diagram 4.21.
Disconnect the pump at the unions.
Discard the sealing washers.
Make sure that the flow direction arrow is pointing upward when
fitting and use the new sealing washers.
Refit water pressure switch, refer to Section 4.9.
The flow adjuster on the new pump should be set to that of the
original, refer also to Section 4.6 in the Installation Instructions.
The flow rate should be controlled by means of a valve in the
heating flow, refer to Section 11.10 in the Installation Instructions.
Note: Should the pump fail to operate, refer to Fault Finding
diagram 3.5. If all is in order, but the pump still does not operate,
remove the end screw, or cap, see diagram 4.21, then turn the
pump spindle to release any temporary seizure.
DO NOT HIT THE SPINDLE.
4.25 Automatic Air Vent
Release the water pressure and drain the central heating circuit
of the boiler, refer to Section 1.3 and 1.6.
Remove the automatic air vent, see diagram 4.22
SLACKEN THE SMALL CAP ON THE AIR VENT. THIS MUST
NOT BE RE-TIGHTENED.
When refitting use the new sealing washer provided.
4.26 Heat Exchanger
Release the water pressure and drain the central heating and
domestic hot water circuits refer to Section 1.3 and 1.6.
Remove the fan from the flue collector, refer to Section 4.1.
Remove the flue collector, secured with two screws, see diagram
4.1.
Remove the main burner, refer to Section 4.2.
Remove the automatic air vent, refer to Section 4.28. If
renewing the heat exchanger, transfer the air vent, using the
new sealing washers provided.
Disconnect the union nuts of the heat exchanger to remove it,
see diagram 4.22.
Locate the raised location tabs on the combustion chamber
sides into the slots on the heat exchanger, see diagram 4.22.
Make sure that the main burner is located on the main injector
and is horizontal, the tips of the rearmost blade under the two
burner guides, see diagram 4.2A.
The combustion chamber front panel should be fitted loosely,
then the flue collector also fitted loosely, ensuring that it is
seated correctly on the heat exchanger and over the top edge
of the front panel.