Expansion Vessel/Pump - Potterton Promax HE Store Installation & Servicing Instructions Manual

4.3 Expansion Vessel, Pump &
Pressure Switch
Re-assemble all parts in reverse order.
1. Check that the cap on the auto air vent is
open. Turn the 3 isolating valves OFF and
locally drain the boilers circuit by opening
the primary pressure relief valve.
2. Disconnect the flexible pipe at the union
below the pump.
3. Pull the expansion vessel forward and
spring the RH side panel slightly to enable
the vessel to be removed.
4. Check the pre-charge pressure of the
replacement vessel is between 1.0 and
1.2 bar before fitting.
5. Reassemble in reverse order.
Pump - Head Only
1. Locally drain the boiler circuit as above
and remove the socket head screws
securing the pump head to the body and
draw the head away.
2. Detach the pump cable.
3. A standard replacement Grundfos 15-60
head can now be fitted. Connect the pump
wiring to the new head.
4. Reassemble in reverse order.
Pump - Complete
1. Drain the primary circuit.
2. Undo the two screws securing the body to
the pipe fittings and draw the pump
forwards.
3. Detach the pump cable.
4. Connect the wiring cable to the new
pump. Examine the O ring seals on the
pipe fittings, replacing if necessary.
IMPORTANT: Leave the cap on the auto air
vent partially unscrewed so that the vent
remains operational.
© Baxi Heating UK Ltd 2012
Expansion Vessel
Connection Pipe
Pump Wiring
Cover
Socket Headed
Screw
Pump Wiring
Cover
Expansion Vessel
Spring
Washer
Pump Body
Pump Head
Automatic
Air Vent
Fig. 18
39