Grundfos MQ User Manual

English (GB)
16
10. Fault finding
If the pump does not start when the fault has been corrected, contact your pump supplier or Grundfos for
further information.
Fault Cause Remedy
1. The pump does
not start.
a) Insufficient water. Check the water supply/suction pipe.
b) Overheating due to excessive liquid
temperature (above +35 °C).
Supply cold liquid to the pump.
c) Overheating due to
seized-up/choked-up pump.
Contact your pump supplier.
d) Too low or too high supply voltage. Check the supply voltage and correct the
fault, if possible.
e) No power supply. Connect the power supply.
f) No water consumption. Open a tap. Check that the height
between the top point of the discharge
pipe and the pump does not exceed
15 metres.
g) The pump is in alarm condition. Reset the pump by means of the on/off
button. See point 2 in the table in section
5.1 Control panel.
2. The pump does
not stop.
a) The existing pipework is leaking or
defective.
Repair the pipework.
b) The non-return valve is blocked or
missing.
Clean the valve or fit a new non-return
valve.
3. The pump cuts
out during
operation.
a) Dry running. Check the water supply/suction pipe.
b) Overheating due to excessive liquid
temperature (above +35 °C).
Supply cold liquid to the pump.
c) Overheating caused by:
– high ambient temperature
(> 45 °C),
– overloaded motor or
– seized-up motor/pump.
Contact your pump supplier.
d) Too low supply voltage. Check the supply voltage and correct the
fault, if possible.
4. The pump cuts
out during
operation. The
"Alarm" indicator
light flashes.
a) Frequent starts/stops caused by
– leakage in suction pipe,
– dripping tap or
– running toilet.
Check the water supply/suction pipe.
5. The pump starts
and stops too
frequently.
a) Leakage in suction pipe or air in the
water.
Check the water supply/suction pipe.
b) Too low or too high pressure in
pressure tank.
Check pressure in pressure tank. See
section 4.1 Operating conditions.
6. The pump gives
electric shocks.
a) Defective earth connection. Connect the earth connection to the pump
in accordance with local regulations.
7. The pump starts
when no water is
consumed.
a) Defective non-return valve or the
existing pipework is leaking or
defective.
Clean the valve or fit a new non-return
valve.
Subject to alterations.

Grundfos MQ Specifications

General

Brand	Grundfos
Model	MQ
Category	Water Pump
Language	English