9
troubleshooting
The table below describes a selection of problems with their
possible causes and solutions, see Table 9.1.
If these solutions do not solve the problem contact your usual
installer or call your nearest Vaillant office.
sYMPtOMs
The system does not restart immediately
The system does not work at all (the ventilation
does not start)
Insufficient cooling or heating
Noise is heard
Smells are generated
Mist or steam come are blown out from the unit
table 9.1
troubleshooting.
VAI 3-MWN-U_EN - 10/14 - Vaillant
POssiBLE caUsEs
When unit is stopped, it won't restart until 3
minutes have elapsed to protect the system
When power is disconnected and reconnected
again, the protection circuit will work for three
minutes to protect the Air conditioning unit
The power lead is not connected correctly
Power supply cut
The fuse has blown
Doors and/or windows open
Heat source nearby (e.g. lots of people in the
room)
The thermostat is set to an excessively high
temperature in cooling mode or excessively low
temperature in heating mode
Obstacle in front of the air inlet or outlet
The ambient temperature has not reached the
designated level
Dirty or blocked air filter
Is there any direct sunlight through the window
during the cooling operation?
During unit operation or when stopping the unit
a gurgling noise may be heard. This noise is
more audible the first 2-3 minutes of operation
A cracking noise is heard during operation
If the noise is loud and comes from the louvers
during the unit operation, the air filters may be
too dirty
This is because the system circulates smells
from the indoor surrounding (furniture,
cigarettes)
During COOL mode or DRY mode operation,
the indoor unit may blow some mist. This is
due to the sudden cooling of the indoor air.
MAINTENANCE
POssiBLE sOLUtiON
Wait 3 minutes before starting the unit again
Wait 3 minutes after inserting the plug and
before starting the unit again
Connect the power lead correctly
Reconnect the power supply
Replace the fuse. Only use the right fuses for
each model. Do not use wire or other material
to replace the fuse. Fires could be caused
Close the doors and/or windows
If possible, remove the heat source
Set the temperature properly
Remove the obstacle to allow the air to
circulate properly
Wait for a few moments
Clean the air filter (the air filter should be
cleaned every 15 days)
Use a curtain to protect the Air conditioning unit
This is normal in an Air conditioning unit. The
noise is caused by the refrigerant flowing in the
system).
This is normal in an Air conditioning unit. The
noise is caused by the casing expanding or
shrinking due to the temperature changes
Clean the air filters properly
This situation does not require any action
This situation does not require any action
EN
- 21 -