Fault Finding Chart - Grundfos MQ Instrucciones De Instalación Y Funcionamiento

10. Fault finding chart

Fault
1. The pump does
not start.
2. The pump does
not stop.
3. The pump cuts out
during operation.
4. The pump starts
and stops too fre-
quently.
5. The pump gives
electric shocks.
6. The pump starts
when no water is
consumed.
If the pump does not start when the fault has been corrected, contact your pump supplier or Grundfos for further
information.
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Cause
a) Insufficient water.
b) Overheating due to excessive liquid
temperature (above +95°F).
c) Overheating due to seized-up/
choked-up pump.
d) Too low or too high supply voltage.
e) No electricity supply.
f) No water consumption.
g) The pump is in alarm condition.
a) The existing pipework is leaking or
defective.
b) The check valve is blocked or missing.
a) Dry running.
b) Overheating due to excessive liquid
temperature (above +95°F).
c) Overheating caused by:
- high ambient temperature (> 113°F),
- overloaded motor or
- seized-up motor/pump.
d) Too low supply voltage.
a) Leakage in suction pipe or air in the
water.
b) Too low or too high pressure in pres-
sure tank.
a) Defective ground connection.
a) Defective check valve or the existing
pipework is leaking or defective.
Remedy
Check the water supply/suction pipe.
Supply cold liquid to the pump.
Contact your pump supplier.
Check the supply voltage and correct the
fault, if possible.
Connect the electricity supply.
Open a tap. Check that the height between
the top point of the discharge pipe and the
pump does not exceed 50 ft.
Reset the pump by means of the on/off
button. See point 2 in the table in section
4.1 Control panel.
Repair the pipework.
Clean the valve or fit a new check valve.
Check the water supply/suction pipe.
Supply cold liquid to the pump.
Contact your pump supplier.
Check the supply voltage and correct the
fault, if possible.
Check the water supply/suction pipe.
Check pressure in pressure tank, see sec-
tion 3.1 Operating conditions.
Connect the ground connection to the
pump in accordance with local regulations.
Clean the valve or fit a new check valve.