15
6. Replacing components
6.1 Removing the pump head
1. Disconnect or TURN OFF the power
supply.
2. Close any isolation valves on either side of
the pump to avoid draining the system of
liquid.
3. Remove the vent plug to relieve any
system pressure retained in the pump.
Exercise caution as the fluid may be
scalding hot and under pressure. Only
after the pressure has been relieved and
the pump drained should you proceed with
the next steps.
4. Disconnect the electrical leads from the
terminal box.
5. Disconnect and remove the conduit from
the terminal box.
6. Loosen and remove the four 5 mm allen-
head screws which connect the pump head
housing to the pump housing.
7. Remove the pump head from the pump
housing. Exercise care as the rotor may
fall out of the stator or pump housing.
8. Clean the machined surfaces in the pump
housing of any foreign material.
6.2 Fitting the pump head
1. Carefully remove the new pump head
assembly from its packaging. Separate the
impeller/rotor assembly from the new pump
head.
2. While holding the thrust bearing plate,
carefully place the impeller/rotor assembly
into the pump housing. The bearing plate
should fit snugly into the lowest machined
surface in the pump housing.
3. Ensure that the impeller/rotor assembly
can rotate freely.
4. Place the O-ring over the rotor and locate it
into the inner diameter of the pump
housing.
5. Carefully place the pump head housing
over the rotor and rotate it so the terminal
box is in the position you wish; see section
3.2.1 Rotating the terminal box.
6. Ensure that the pump head housing is
properly seated on the pump housing. Do
not force the two together — if there is
binding, disassemble them and repeat
steps 2 to 6. Cross-tighten the allen-head
screws evenly.
Torque to: 7 ft lb / 9.5 Nm.
7. Check to make sure the rotor turns freely.
Do this by removing the vent plug in the
middle of the pump nameplate. Insert a
medium-size, flat-blade screwdriver into
the slot at the exposed end of the shaft.
Gently turn the shaft. If it does not turn
easily, repeat steps 1 through 6 above.
If the rotor spins freely, proceed to step 8.
Do not put the vent plug back into the
pump until the end of step 10.
8. The position of the nameplate can be
changed by easing the outer edge of the
plate at the cutout with a screwdriver. Turn
the nameplate to the required position and
push into place.
9. Follow electrical instructions in section
3.3 Electrical connection.
10. Refill the system, open the isolation valves
and vent the system. Also allow air to vent
out of the pump, once water flows out the
vent hole, replace the vent plug removed in
step 7. See additional instructions in
section 4.1 Vent the piping system.
Fig. 13 Removing and fitting the pump head
Warning!
Before starting any work on this
circulator, make sure electrical
supply has been switched off and
that it cannot be accidentally
switched on.
T
M
04
56
42
36
09
O-ring
Allen
screws
(4) 5 mm
Terminal box
Bearing plate
Pump housing
Impeller
Rotor assembly
Thrust bearing
Pump head/stator housing
