10 Faults, causes and remedies
Faults, particularly those affecting the pumps or
the control system, should only be remedied by
Wilo customer service or a specialist company.
Fault
Pump(s) do not start
Pump(s) do not switch off
Switching frequency too high or flutte-
ring
Installation and operating instructions Wilo-SiBoost Smart (FC) ... Helix V/... Helix VE/... Helix EXCEL
Cause
No mains voltage
Main switch "OFF"
Water level in break tank too low, i.e.
low-water level reached
Low-water level switch has triggered
Low-water level switch defective
Electrodes incorrectly connected or sup-
ply pressure switch incorrectly set
Intake pressure exceeds start-up pres-
sure
Check valve closed at pressure sensor
Start-up pressure set too high
Fuse defective
Motor protection has triggered
Contactor defective
Turn-to-turn fault in motor
Intake pressure fluctuates severely
Intake pipe blocked or shut off
Nominal diameter of inlet pipe too small Check the inlet pipe, increase the cross-
Inlet pipe incorrectly installed
Air in inlet
Impellers blocked
Non-return valve leaking
Non-return valve blocked
Gate valve in system closed or not suf-
ficiently open
Volume flow too large
Check valve closed at pressure sensor
Switch-off pressure set too high
Direction of motor rotation false
Intake pressure fluctuates severely
Intake pipe blocked or shut off
Nominal diameter of inlet pipe too small Check the inlet pipe, increase the cross-
NOTE!
The general safety instructions must be observed
when doing any maintenance or repair work. Also
follow the installation and operating instructions
of the pumps and the control device.
Remedy
Check fuses, cables and connections
Switch on the main switch
Check break tank inlet valve/inlet pipe
Check intake pressure
Check, if necessary replace the low-
water level switch
Check installation or setting and correct
Check settings and
correct if necessary
Inspect, open check valve
if necessary
Check setting and correct if necessary
Check fuses and replace if necessary
Check set values against the pump or
motor data, measure current values and
correct setting if necessary. Check
motor for defects and replace if neces-
sary
Check and replace if necessary
Check, if necessary replace motor or
have repaired
Check intake pressure, if necessary take
measures to stabilise supply pressure
(e.g. pressure reducer)
Check inlet pipe, if necessary remove
blockage or open check valve
section for the inlet pipe if necessary
Check inlet pipe, if necessary change
pipe guide
Check, if necessary seal pipe. Vent
pumps
Check pump, if necessary replace or have
repaired
Check, if necessary replace seal or
replace non-return valve
Check, if necessary remove blockage or
replace non-return valve
Check, open the check valve completely
if necessary
Check pump data and default values and
correct if necessary
Inspect, open check valve if necessary
Check setting and correct if necessary
Check the direction of rotation and cor-
rect by changing over the phases if
necessary
Check intake pressure, if necessary take
measures to stabilise supply pressure
(e.g. pressure reducer)
Check inlet pipe, if necessary remove
blockage or open check valve
section for the inlet pipe if necessary
English
43