Cleaning The Pump; Contaminated Pumps; Replacement Of Parts - Grundfos Unilift AP12 Installation And Operating Instructions Manual

7.1 Cleaning the pump

If the pump does not deliver a sufficient quantity of
water because of sediment, dismantle and clean the
pump.
To dismantle the pump, follow this procedure:
1. Disconnect the power supply.
2. Lift the pump out of the liquid and allow it to
drain.
3. Carefully loosen the inlet strainer (84) by
inserting a screwdriver through one of the holes
of the strainer and press it downward. Repeat the
procedure until the strainer is free and can be
removed.
4. Remove the inlet strainer, clean, and refit it.
5. Place the pump on its base in the liquid.
6. Connect the power supply and start the pump.
If the pump still does not deliver sufficient water,
dismantle the pump:
1. Disconnect the power supply.
2. Lift the pump out of the liquid and allow it to
drain.
3. Carefully loosen the inlet strainer (84) by
inserting a screwdriver through one of the holes
of the strainer and press it downward. Repeat the
procedure until the strainer is free and can be
removed.
4. Remove the inlet strainer and clean it.
5. Unscrew the six screws (188a) close to the edge
of the pump sleeve (55) and lift the pump housing
(6) out of the pump sleeve.
6. Clean the pump housing, the pump, and the
impeller (49).
7. Check to make sure the impeller can rotate
freely. If not, remove the impeller:
– Hold the impeller in place with a screwdriver
while loosening and removing the lock nut (67)
on the shaft.
– Clean the impeller and the shaft.
8. Check the impeller and the shaft. If the impeller is
worn or defective, replace it.
9. Assemble the pump in the reverse order of
dismantling:
– Fit the impeller (49) with the washer and lock
nut (67). Make sure the impeller engages with
the shaft.
– Position the O-ring (37a) in the pump sleeve
and lower the pump onto the pump housing.
– Fit the six screws (188a) in the pump housing
(6) and tighten securely.
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7.2 Contaminated pumps

Any application for service (no matter to whom it may
be made) must include details about the pumped
liquid.
CAUTION
Biological hazard
Minor or moderate personal injury
- Flush the pump thoroughly with
clean water and rinse the pump
parts in water after dismantling.
The product will be classified as contaminated if it
has been used for a liquid which is injurious to health
or toxic.
If you request Grundfos to service the product,
contact Grundfos with details about the pumped
liquid before returning the product for service.
Otherwise Grundfos can refuse to accept the product
for service.
Any application for service must include details
about the pumped liquid.
Clean the product in the best possible way before
you return it.
Costs of returning the product are to be paid by the
customer.

7.3 Replacement of parts

The impeller assembly and power cable can be
replaced. The part numbers and the components
included in the service kits can be found on Grundfos
Product Center (www.grundfos.us). Alternatively,
contact your local Grundfos dealer or service center.