
6
Pump
Troubleshooting
2. Impeller or volute openings
may be plugged or partially
plugged. Remove pump and
clean out.
3. Pump impeller may be partially
clogged causing motor to
run slow, resulting in motor
overload. Clear impeller.
4. Fuse size or circuit breaker is
too small.
5. Defective motor stator: return
to authorized Hydromatic
service center for verification.
Motor runs for short time
then stops. Then after short
period starts again. Indicates
tripping overload caused by
symptom shown.
1. Inlet in pump base may be
clogged. Remove pump and
clean out openings.
2. Impeller or volute openings
may be plugged or partially
plugged. Remove pump and
clean out.
3. Pump impeller may be partially
clogged causing motor to
run slow, resulting in motor
overload. Clear impeller.
4. Defective motor stator: return
to authorized Hydromatic
service center.
2. Switch contacts may be stuck;
replace switch.
Pump runs but delivers only
small amount of water.
1. Pump may be air locked. Start
and stop several times by
plugging and unplugging cord.
Check vent hole in pump case
for plugging.
2. Pump head may be too
high. Pump cannot deliver
water over 24' vertical lift.
Horizontal distance does
not affect pumping, except
loss due to friction through
discharge pipe.
3. Inlet in pump base may be
clogged. Remove pump and
clean out openings.
4. Impeller or volute openings
may be plugged or partially
plugged. Remove pump and
clean out.
5. Pump impeller may be partially
clogged causing motor to
run slow, resulting in motor
overload. Clear impeller.
Fuse blows or circuit breaker
trips when pump starts.
1. Inlet in pump base may be
clogged. Remove pump and
clean out openings.
Check vent hole in pump case
for plugging.
Hydromatic pumps have a
small air vent hole in the
impeller cavity to let out
trapped air. If this hole
becomes plugged, pump may
air lock. To break the air lock,
use a small screwdriver to
clear hole in the impeller
cavity.
As a secondary precaution in
installations of this type —
1/16" hole should be drilled in
the discharge pipe below the
check valve. The check valve
should be 12 to 18 inches
above pump discharge. Do not
put check valve directly into
pump discharge opening.
NOTE: In sumps where the
pump is operating daily, air
locking rarely occurs.
4. Pump head may be too high.
Pump cannot deliver water
over 24' vertical lift.
Horizontal distance does not
affect pumping, except for
friction loss through the pipe.
5. Inlet in pump base may be
clogged. Remove pump and
clean out openings.
6. Impeller or volute openings
may be plugged or partially
plugged. Remove pump and
clean out.
Pump runs and pumps out
sump but does not stop.
1. Float is stuck in up position.
Be sure float is not hung up
and operates freely in basin.
Capacity-U.S. G.P.M.
Liters/Second
0
30
60
90
120
150
180
0
2
4
6
8
10
HEAD-FEET
HEAD-METERS
0
10
40
30
20
0
3
12
9
6
1/2 HP
SKV50 PERFORMANCE CURVE