Fault Finding Chart - Grundfos MQ series Montage- Und Betriebsanleitung

9. Fault finding chart

Fault Cause
1. The pump does not a) Insufficient water.
start.
b) Overheating due to excessive liquid
temperature (above +35°C).
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.
2. The pump does not a) The existing pipework is leaking or
stop. defective.
b) The non-return valve is blocked or
missing.
3. The pump cuts out a) Dry running.
during operation.
b) Overheating due to excessive liquid
temperature (above +35°C).
c) Overheating caused by:
- high ambient temperature (> 45°C),
- overloaded motor or
- seized-up motor/pump.
d) Too low supply voltage.
4. The pump cuts out a) Frequent starts/stops caused by
during operation. - leakage in suction pipe,
The "Alarm" indica- - dripping tap or
tor light flashes. - running toilet.
5. The pump starts a) Leakage in suction pipe or air in the
and stops too fre- water.
quently.
b) Too low or too high pressure in pres-
sure tank.
6. The pump gives a) Defective earth connection.
electric shocks.
7. The pump starts a) Defective non-return valve or the ex-
when no water is isting pipework is leaking or defec-
consumed. tive.
If the pump does not start when the fault has been corrected, contact your pump supplier or Grundfos for
further information.
110
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 be-
tween the top point of the discharge pipe
and the pump does not exceed 15 metres.
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 non-return
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 the water supply/suction pipe.
Check pressure in pressure tank, see
section 3.1 Operating conditions.
Connect the earth connection to the pump
in accordance with local regulations.
Clean the valve or fit a new non-return
valve.
Subject to alterations.