Instruction manual
5. Trouble shooting
Pump problem Possible reason - horizontal pump Possible reason - vertical pump
No liquid ow 2-3-4-5-6-7-8-12-15-22-24-31 4-5-7-8-12-15-17-22-24-28-31
Insufcient liquid ow 1-3-6-8-10-11-13-14-15-16-18-19-20-25-28-29 8-10-13-14-15-16-18-19-20-25-28-29-30
Insufcient pressure 8-10-13-14-15-16-18-20-25-29-30 10-13-14-16-18-30-25-29-30
Rising liquid temperature 8-15-19-25 8-15-18-19
Noisy pump or excessive vibration 1-3-6-13-14-15-20-21-22-23-28-34 9-13-14-15-16-17-21-22-23-32
Motor is overheating 13-15-16-20-21-22-23-24-25-27-28-29-30 15-16-21-22-23-24-25-27
Motor overload activated 20-25-26-28-29-30 22-25-26-29-30
Cracking/deformation 9-34-49 9-34-49
Corrosion 27-50 27-50
Filter problem Possible reason
No or insufcient liquid ow 8-19-28-38-39-41-42-48
Leakage 39-40-49
Pressure gauge reading not correct 35-36-37-38
High dial indication on pressure gauge 8-42-48
Bad ltering result 33-42-43-45-47
Foam formation in the bath 11-31-46
System / Pipework Liquid
1 Suction pipe too long or diameter too small 28 Liquid has crystallised
2 Air pocket in suction pipe 29 Specic gravity of liquid too high
3 Leak in suction pipe 30 Viscosity of liquid too high
4 Suction pipe or strainer blocked 31 Air / gas in liquid
5 Suction height too high 32 Abrasive particles in liquid
6 Air supply close to suction inlet 33 Colloïdal liquid
7 Foot valve or suction pipe insufciently submerged 34 Liquid temperature too high
8 Valve in pipework (partly) closed
9 Discharge pipe under tension
10 Leak in discharge pipe Filter
11 Return pipe not submerged (air intake) 35 Not enough anti-freeze in chamber below pressure gauge
12 Liquid level in tank too low 36 Membrane in chamber below pressure gauge deformed/damaged
37 Pressure gauge defect
Pump 38 Filter chamber insufciently bled
13 Impeller damaged or worn out by abrasives 39 Filter chamber not closed properly
14 Impeller out of balance 40 Filter chamber gasket damaged of deformed
15 Impeller / volute blocked by foreign matter 41 Filter element incorrectly installed
16 Wrong impeller choice (50 or 60 Hz) 42 Filter system element saturated
17 Volute not immerged sufciently in the liquid 43 Bypass of unltrated liquid
18 Wrong choice of pump size 44 Filter medium is too coarse
19 Pump is running at very low ow 45 Filter material damaged or torn
46 Unwashed cartridges used (residues of wetting agents)
47 Wrong choice of lter medium
Motor 48 Wrong choice of micron rating
20 Wrong direction of rotation
21 Cooling fan blocked or loose
22 Motor bearings jammed or worn out Material / Environment
23 Motor bearings incorrectly installed 49 Wrong choice of pump / o-ring material
24 Motor down on a phase 50 Aggressive environment
25 Incorrect voltage
26 Thermal overload setting incorrect
27 Insufcient cleaning
© Hendor - Quality Pumps & Filters - 9 - Info 28640/R0