Change Of Pump; Change Of Complete Pump; Open Flued Boiler; Balanced Flued Boiler - Vaillant VCW 2O Instructions For Installation And Servicing

8.18 Ghange ot pump
8.18.1 Change of complete pump
Drain the appliance as under 8.'l and 8.1.2.
lsolate the appliance from the electrical mains.
Open the terminal box of the pump. Note the
colour code of wiring and disconnect pump
connection cable.
Unscrew the automatic air vent (Pl ) by hand.
Mark and disconnect the 2 control lines of the
automatic valve by unscrewing the tubing nuts
(P2). Loosen the 2 pump unions (P3) and
unscrew the bracket fixing screw (P4) and the
union nut (P5) at the right hand connection to
the main heat exchanger.
8.18.1.1 Open flued boiler
Take otf connection to main heat exchanger
together with the pump as shown on fig. 75.
Reassemble in reverse order, using new
washer at the right hand connection to the maln
heat exchanger.
Screw in the automatic air vent by hand only.
Check - earth continuity
- polarity
- resistance to earth
according to INSTRUCTIONS FOR BRITISH
GAS MULTIMETER.
8.18.1.2 Balanced flued boiler
Unscrew the upper pump union (P3) and spring
off the pump as shown in fig. 76. Reassemble in
reverse order, using new washer at the right
hand connection to the main heat exchanger.
Screw in the automatic air vent by hand only.
Check - earth continuity
- PolaritY
- resistance to earth
according to INSTRUCTIONS FOR BRITISH
GAS MULTIMETER.
5 .
38