Sotera DEF - Manual (Page 8)

8
Symptom Cause Cure
Pump won't
prime.
1. Suction line problem. Check for leaks in suction line
2. Bypass valve open. Remove and inspect valve; must move
freely & be free of debris.
3. Vanes sticking. Check vanes and slots for nicks, burrs
and wear.*
5. Excessive rotor or vane wear. Inspect rotor & vanes for excessive wear
or damage; replace if necessary.*
6. Outlet blocked. Check pump outlet, hose, nozzle & filter
for blockage.
7. Vapor Lock Reduce vertical and horizontal distance
from pump to liquid; remove automatic
nozzle.
Low capacity.
1. Excessive dirt in screen. Remove and clean screen.
2. Suction line problem. Check suction line for leaks or
restrictions; it may be too small, too long
or not airtight.
3. Bypass valve sticking. Remove and inspect valve; must move
freely & be free of debris.
4. Vanes sticking. Check vanes and slots for wear.
5. Excessive rotor or vane wear. Inspect rotor & vanes for excessive wear
or damage; replace if necessary.*
6. Hose or nozzle damage. Replace hose or nozzle.
Pump runs
slowly.
1. Incorrect voltage. Check incoming line voltage while pump
is running.
2. Vanes sticking. Inspect vanes and slots for nicks, burrs
and wear.*
3. Wiring problem. Check for loose connections.
4. Motor problem. Return to place of purchase.
Motor stalls.
1. Bypass valve sticking. Remove and inspect valve; must move
freely & be free of debris.
2. Low voltage. Check incoming line voltage while pump
is running.
3. Excessive rotor or vane wear. Check rotor & vanes for excessive wear
or damage.*
4. Debris in pump cavity. Clean debris from pump cavity.
2. Clogged screen. Remove and clean screen.
3. Restricted suction pipe. Remove and clean pipe.
4. Motor failure. Return to place of purchase.
5. Pump rotor lock-up. Clean and check pump rotor and vanes.
Motor
Inoperative.
1.No power Check incoming power.
2. Switch failure. Return to place of purchase.
3. Motor failure. Return to place of purchase.
4. Incorrect/loose wiring. Check wiring.
Fluid leakage.
5. Bad o-ring gasket. Check all o-ring gaskets.
6. Dirty shaft seal. Clean seal & seal cavity.
7. Bad shaft seal. Replace seal.
8. Incompatible fluid. Refer wetted parts list to fluid
manufacturer.
9. Loose fasteners. Tighten fasteners.
Pump hums
but will not
operate.
10. Motor Failure Return to place of purchase.
11.Broken Key. Remove any debris and replace key.
12. Rotor Vanes locked in DEF
crystals. *
See detailed explanation on page 9.