Glow-worm SwiftFlow 120 Servicing Instructions page 18

4.9 Pump
Release the water pressure and drain the central heating
circuit of the boiler, refer to Section 1.3 and 1.6.
Disconnect the electrical connectors at the water pressure
microswitch. Remove the water pressure switch, refer to
Section 4.8.
Remove the terminal cover from the pump and
disconnect the cable, see diagram 4.5.
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 4.8.
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 diagram
3.8. If all is in order, but the pump still does not operate,
remove the end screw, see diagram 4.5, then turn the
pump spindle to release any temporary seizure.
DO NOT HIT THE SPINDLE.
4.10 Domestic Hot Water High Limit Control
Remove the pump, see Section 4.9.
Disconnect the electrical connectors at the domestic hot
water high limit control, see diagram 4.6.
Remove the high limit control from the flow pipe,
secured with two screws.
Use the heat sink compound supplied, between the
mounting plate and the control.
When refitting the electrical connections to the high limit
control the polarity is not important, see diagram 4.11.
4.11 Piezo Unit
Remove the piezo unit bracket, see diagram 4.3.
Disconnect the ignition lead at the piezo unit.
Remove the piezo unit from the bracket.
221045A
Supplied By www.heating spares.co Tel. 0161 620 6677
4 R e p l a c e m e n t o f P a r t s
PUMP
SPINDLE
END
SCREW
D.H.W. HIGH LIMIT CONTROL
18
PUMP
ADJUSTER
TERMINAL COVER
SCREW
FLOW DIRECTION
ARROW
ELECTRICAL
CONNECTORS
SECURING
SCREW (2)
UPPER
PUMP
UNION
LOWER
PUMP
UNION
Diagram 4.5
D.H.W.
HIGH
LIMIT
CONTROL
Diagram 4.6