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.