12
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6
9.2 Pump
9.3 Pressure switch
10. Disposal
This product or parts of it must be disposed of in
an environmentally sound way:
1. Use the public or private waste collection
service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
Subject to alterations.
Problem
Possible cause
Possible remedy
1.
The pump does not
deliver.
a)
The pump has not been primed
correctly.
Review section
6.1 Startup
.
b)
The diameter of the intake pipe is
insufficient.
Replace the pipe with a larger
diameter one.
c)
Blocked foot valve.
Clean the foot valve.
2.
The pump does not
prime.
a)
The intake pipe or the foot valve
is taking in air.
Correct the problem and prime
again.
b)
The downward slope of the
intake pipe favors the formation
of air pockets.
Correct the inclination of the
intake pipe.
3.
The pump supplies
insufficient flow.
a)
Blocked foot valve.
Clean the foot valve.
b)
The impeller is worn or blocked.
Remove the obstructions or
replace the worn parts.
c)
The diameter of the intake pipe is
insufficient.
Replace the pipe with one with a
larger diameter.
4.
The pump vibrates
and operates
noisily.
a)
Check that the pump and the
pipes are firmly anchored.
Fix the loose parts more carefully.
b)
There is cavitation in the pump,
that is the demand for water is
higher than it is able to pump.
Reduce the intake height or check
for load losses.
c)
The pump is running above its
plate characteristics.
It may be useful to limit the flow at
delivery.
Problem
Possible cause
Possible remedy
5.
The pressureswitch
starts and stops
frequently during
normal water
delivery.
a)
Check the setting of the pressure
switch to see if it is too low.
Increase the setting values of the
pressure switch until the problem
is overcome.
Do not forget to reset the
minimum intervention pressure.
b)
Check that the diaphragm of the
expansion chamber (if used) is
unbroken.
Otherwise remove the fault.
