COMMON FAILURES AND TREATMENT
Malfunction
Possible cause
Elimination
The pump is not
discharging any
liquid, the motor is
not running.
Thermal motor protection feature has
triggered. (for information on operation with
liquids > 50°C, see the note in Technical
data).
Separate the pump from the electrical
mains, allow the system to cool down,
eliminate cause.
The min. suction level was fallen short of;
Make sure that the minimum suction level is
not fallen short of; if necessary, adjust floating
switch properly or make sure that it can move
freely; in the case of a defective floating switch,
check the output hose is not blocked or crimped
please contact customer service.
The capacitor is defective.
Please contact the customer service
department.
The pump wheel is blocked.
Eliminate blocking of pump wheel.
Please contact the customer service
department.
The motor is
running, but
the pump is not
discharging any
liquid.
The intake openings are clogged.
Remove possible congestion.
The pressure line is clogged or kinked.
Remove possible congestion / kink in the line.
Air penetrates into the pump body.
Start pump several times so that the entire
air will be driven out.
Check valve (non-return valve), if present,
is blocked or defective.
Eliminate blocking of the check valve
(nonreturn valve) or replace, if damaged.
The pump stops
after a short
time of operation
because the
thermal motor
protection feature
has triggered.
Pump or intake openings are blocked by
solids.
Remove possible congestion.
Liquid is too viscous.
Pump may not be suitable for this liquid. If
feasible, the liquid should be thinned.
Temperature of the liquid is too high.
Make sure that the temperature of the
liquid being pumped does not exceed the
max. admissible value.
Pump is running dry.
Eliminate causes of dry-running.
Intermittent
or irregular
operation.
Pump wheel obstructed by solid matters. Remove solids.
Mains voltage out of tolerance.
Make sure that mains voltage matches that
indicated on the type plate.
Motor or pump wheel defective.
Please contact the customer service
department.
The pump does
not cut in or out.
Floating switch cannot move freely.
Floating switch defective.
Please contact the customer service
department.
