"Bus fault" message is
displayed and the unit
operates at speed 1
(check the fan speed).
• Wiring fault in the carbon dioxide sensor,
in the control panel or in the humidity
sensor.
9
• Contact a maintenance company. The connections have
to be checked and corrected if necessary.
"Freezing alert" message
is displayed and the unit is
stopped.
• Antifreeze of the water-circulating radiator
is active.
NOTE! If there is no non-freezing solution in the
water of the radiator, the radiator is at risk of
freezing.
10
• Immediately troubleshoot the situation. Consult a
maintenance company to find out if there is any non-
freezing solution in the radiator. Check if the circulation
pump is broken, the boiler out of operation etc. The
situation may pass by itself as soon as supply air
temperature exceeds 10 degrees, but do not wait till it
happens.
The desired automatic
adjustment does not stay
on.
• There is a fault in the humidity or carbon
dioxide sensor. One of the sensors is
broken or missing.
11
• Contact a maintenance company. Sensor mounting and
connections have to be checked. (The sensors are
optional.)
The unit does not work,
the fans are not running
and no indicator light is lit
in the control panel.
• The door switch may be broken, or the
door is possibly not quite closed.
• The unit is out of power, e.g. because a
fuse has blown.
• The glass tube fuse (located in the control
card behind a protecting plate) protecting
the electronics inside the unit may have
blown.
12
• Check the door switch and fuses. The unit includes a
T800 mA glass tube fuse.
• If needed, contact a maintenance company (e.g. to
check the glass tube fuse)
The unit does not obey
the control panel.
13
• Disconnect the plug of the unit from the wall socket, wait
for 30 seconds and put the plug back. If this does not
help, contact a maintenance company.
"Carbon dioxide alarm"
message is displayed and
the unit has stopped.
• Carbon dioxide alarm. Carbon dioxide
content has exceeded 5000 PPM for two
minutes. May be caused by a fire.
14
• If there is a fire, take the necessary steps.
• You can make the unit operational by disconnecting the
plug from the wall socket, waiting for 30 seconds and
putting the plug back again.
• Check the cleanliness of the filters and the unit. If needed,
clean or replace the filters. Also check the external grille.
15
The filter guard symbol
( ) is displayed and the
unit operates otherwise
normally.
• The pressure in the filter guard (pressure
difference switch) has risen above the
adjustment value or speed is 7 or 8.
SYMPTOM
REASON
DO THIS
© VALLOX • We reserve the right to make changes without prior notice.
1.09.395E/9.2.2011/PDF
VALLOX DIGIT2 SE
TROUBLESHOOTING
Vallox Oy • Myllykyläntie 9-11• FI-32200 Loimaa • Tel. +358 10 7732 200 • www.vallox.com
After a power failure, the unit starts at minimum fan speed. All the other selected adjustments
and setpoints remain in the memory of the unit.
