Fault Finding The Product - Grundfos Unilift CC 5 Installation And Operating Instructions Manual

6. Fault finding the product

DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before
starting any work on the product. Make
sure that the power supply cannot be
accidentally switched on.
Fault Cause
1. The pump does a)
not run.
b)
c)
2. The pump stops a)
after a short
time of
operation (the
thermal switch
b)
has tripped).
c)
3. The pump runs, a)
but gives
insufficient
b)
water.
4. The pump runs, a)
but gives no
b)
water.
c)
10
The power supply is switched off.
The fuses in the installation are
blown.
The pump thermal switch has tripped.
See section 3.5 Thermal
(See also point 2.)
The temperature of the pumped liquid
is higher than that stated in section
7. Technical data. The motor is
overheated.
The pump is partly or fully blocked by
impurities.
The water level is too low when the
pump is started. The pump cannot
self-prime. See section 7. Technical
data.
The pump is partly blocked by
impurities.
The outlet pipe or hose is partly
blocked by impurities.
The hose may be sharply bent.
The pump is blocked by impurities.
The non-return valve in the outlet
pipe or hose is blocked in closed
position or blocked by impurities.
The hose may be sharply bent.
Pumps with float switch: The pump
does not stop because the free cable
length of the float switch is too long.
Remedy
Switch on the power supply.
Replace defective fuses.
The thermal switch restarts the pump
protection. when the motor has cooled down to
normal temperature.
The pump starts automatically after
sufficient cooling.
Clean the pump.
Move the pump to a position with higher
water level, or add water until the pump
starts sucking.
Clean the pump.
Check and clean the non-return valve, if
fitted.
Straighten out the hose.
Clean the pump.
Check the non-return valve.
Clean or replace the valve, if necessary.
Straighten out the hose.
Reduce the free cable length.