"Bus fault" message is
displayed and the unit ope-
rates 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.
• Anti-frost 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. The sensor installation
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) 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
• Remove or switch off the power supply fuse of the unit,
located in the distribution panel, or the circuit breaker.
Wait for 30 seconds and put the fuse back, or switch the
circuit breaker on. If this does not help, contact a
maintenance company.
"Carbon dioxide alarm"
message is displayed and
the unit is stopped.
• Carbon dioxide alarm. Carbon dioxide
content has exceeded 5000 PPM for more
than two minutes. May be caused by a
fire.
14
• If there is a fire, take the necessary steps.
• You can put the unit in working order by disconnecting the
plug from the wall socket, waiting for 30 seconds and
connecting the plug again.
• Check the cleanliness of the filters and the unit. If needed,
clean or replace the filters.
15
© VALLOX • We reserve the right to make changes without prior notification.
1.09.372E/19.8.2008/PDF
VALLOX 280 SE
Vallox Oy FIN-32200 Loimaa Finland Tel358 2 7636 300 Fax +358 2 7631 539
Internet: www.vallox.com.
FAULT SITUATIONS
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.
The filter guard symbol
( ) is displayed and the
unit operates otherwise
normally.
• Pressure in the filter guard (pressure
difference switch) has exceeded the
setpoint.
SYMPTOM
REASON
DO THIS
