Troubleshooting
en
Installation and operating instructions Wilo-Yonos MAXO-Z
15
▪ Disconnect all-pole power supply before starting work.
▪ Begin work at least 5 minutes after disconnecting the
power supply.
8.3
Error table
Fault
Cause
Correction
Pump is not running
with switched-on
power supply.
Fuse protection de-
fect.
Check fuse.
No voltage.
Check voltage.
Pump makes
noises.
Cavitation due to
insufficient suction
pressure.
Maintain pressure/
increase system
pressure. Observe
permissible pres-
sure range.
Check the delivery
head and adjust
where necessary.
Hot water does not
get warm within a
short period of
time.
Setpoint set too
low.
Increase setpoint.
Set operating mode
Δp-c.
8.4
Fault signals
▪ A signal is displayed.
▪ The fault signal LED lights up.
▪ The SSM contact opens.
▪ Switch off the pump and try a restart at regular inter-
vals. During E10 switch off the pump permanently after
10 minutes.
No.
Fault
Cause
Remedy
E04
Undervoltage
Power supply on
mains side too
low.
Check mains
voltage.
E05
Overvoltage
Power supply on
mains side too
high.
Check mains
voltage.
E09
1)
Turbine opera-
tion
Pump is operated
backwards.
Check the flow
and install non-
return valve if
necessary.
E10
Blocking
Rotor blocked.
Contact cus-
tomer service.
E21
2)
*
Overload
Slow motor.
Contact cus-
tomer service.
E23
Short-circuit
Motor current
too high.
Contact cus-
tomer service.
No.
Fault
Cause
Remedy
E25
Contacting/
winding
Winding defect-
ive.
Contact cus-
tomer service.
E30
Excessive tem-
perature of mod-
ule
Interior of mod-
ule too warm.
Check operating
conditions.
E31
Excessive power
section temper-
ature
Ambient tem-
perature too
high.
Check operating
conditions.
E36
Electronics errors Electronics de-
fective.
Contact cus-
tomer service.
If a fault cannot be repaired, contact a qualified spe-
cialist or customer service.
1)
Only for pumps with P1 ≥ 200 W
2)
In addition to the LED display, the fault signal LED is
continuously illuminated in red.
*
See also warning signal E21
8.5
Warning signals
▪ A signal is displayed.
▪ Fault signal LED does not light up.
▪ The SSM contact does not open.
▪ The pump is running at reduced performance.
No.
Fault
Cause
Remedy
E07
Generator opera-
tion
Pump hydraulics
have fluid run-
ning through
them.
Check unit.
E11
Dry run
Air in the pump.
Check liquid
pressure and
volume.
E21
*
)
Overload
Slow motor.
Pump is operated
beyond its spe-
cifications (e.g.
high module
temperature).
The speed is
lower than dur-
ing normal oper-
ation.
Check ambient
conditions.
1)
Only for pumps with P1 ≥ 200 W
*
See also fault signal E21
