WDM AG Series, Operation Manual

Page: 23 / 28

Self-Priming Pumps.
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8. Troubleshooting.
Symptom Possible cause(s) Possible solution(s)
Little or no discharge and unit
will not prime.
1. Casing not filled with water.
1. Fill pump casing. Using a foot
valve will extend pump life and
facilitate immediate priming.
2. Total head too high. 2. Shorten suction head.
3. Suction head higher than
pump designed for. 3. Lower suction head, install
foot-valve and prime.
4. Impeller partially or
completely plugged. 4. Disassemble pump and clean
out impeller.
5. Hole or leak in suction line. 5. Repair or replace suction line.
6. Foot-valve too small.
6. Match foot-valve to piping or
install one size larger foot-valve.
7. Impeller damaged.
7. Disassemble pump and
replace impeller.
8. Foot-valve or suction line
not submerged deep enough
in water; pulling air.
8. Submerge lower in water.
9. Insufficient inlet pressure or
suction head.
9. Increase inlet pressure by
adding more water to tank or in-
creasing back pressure by turning
gate valve on discharge line to
partially closed position.
10. Suction piping too small
10. Increase pipe size to pump
inlet size or larger.
11. Casing gasket leaking 11. Replace.
12. Suction or discharge line
valves closed.
12. Open.
13. Piping is fouled or
damaged.
13. Clean or replace.
14. Clogged strainer or
foot valve.
14. Clean or replace.
Loss of suction after
satisfactory operation.
1. Air leak in suction line. 1. Repair or replace suction line.
2. When unit was last turned
off, water siphoned out of
pump casing.
2. Refill (reprime) pump casing
before restarting.
3. Suction head higher than
pump designed for. 3. Lower suction head; install
foot-valve and primer.