VALLOX 90 SE
15
TROUBLESHOOTING
"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 sen-
sor.
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.
• Antifreezing of the water-circulating ra-
diator is active
(not in the VALLOX 90 SE unit).
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. Find out from a main-
tenance company if there is 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 bro-
ken or missing.
11
• Contact a maintenance company. The sensor installation
and connections have to be checked. (The sensors are optio-
nal.)
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 electro-
nics 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 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 make the
unit operative 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
SYMPTOM
REASON
DO THIS
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 ad-
justment value or speed is 7 or 8.
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.
Summary of Contents for 90 SE Series
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