19
MDR/EN (0909) 1.0
6.0 Trouble shooting chart
Problem
Possible cause
Remedy
No flow
Air pockets in suction lines
Check piping of suction
lines and work out all air
Lack of prime (when suc-
tion head is negative)
Prime again
Air pockets inside the
pump
Work out all air
Insufficient suction head
See section 2.2.1
Slipping magnet coupling
Excessive specific gravity
and/or viscosity - check
against original specifica-
tion (see point 2.7)
Wear or damage of parts
Replace parts
No liquid in the pump
Check liqud level in the
tank. If a foot valve is
installed on the suction line
make sure that it is properly
sealed. Fill the pump again.
Underfeed
Air entrainment or air
pockets
Check joint sections of suc-
tion lines. Work out all air
Run reverse
Check direction of rotation
Excessive piping loss
Reduce suction line length
or increase diameter
Impeller is clogged with
foreign materials
Remove foreign materials
Excessive power
Excessive specific gravity
and/or viscosity
Check viscosity and specific
gravity against pump per-
formance (see section 2.7).
Excessive wear of pump
parts
Replace parts
Excessive wear of motor
bearings
Replace bearings/motor
Excessive vibration or
noise
Wear or damage of parts
Replace parts
Short of head
Increase discharge head
(see section 2.3)
Impeller is clogged with
foreign materials
Remove foreign materials
