Troubleshooting - Mitsubishi Electric VL-250CZPVU-R-E Instruction Manual

7. Troubleshooting

Take the following actions if trouble shown in the table below occurs.
If trouble is not corrected even after taking the required action, or if trouble other than that indicated in the
following table occurs, turn OFF the isolator, and then contact your dealer or an electrical contractor.
Symptom
No operation
There is a sound from the
product
Operating noise has
increased
Air flow has reduced
Burbling noise from the
product
Noise fluctuates
Dew condensation water in
the filter case
The volume of the operating
noise is different in different
rooms
During winter season,
Sometimes supply air stops.
Supply air flow is cold
Small insects intrude into the
indoor through the supply air
vent.
Condensation occurs on the
outside of the product.
Inside the product or the filters
are wet.
Condensation occurs on the
outlet of the supply air vent.
The air volume increases/
decreases without any
command.
When the controller is not working:
Symptom
The OFF button does not
function to stop the product.
Ventilation mode (bypass,
auto bypass) cannot be
selected.
The fan speed ( , , ,
or ) cannot be selected.
The air volume is changed
without any command.
The air volume is not changed
even when the product fan
speed is changed.
Cause
Power is not supplied to the product.
The button on the controller is not [ON].
The sound of fans moving and the sound of winds
flowing.
The filter is not installed securely.
The filter is clogged.
The outdoor hood is blocked.
The filter is clogged.
Dew condensation water in the drain pipes is sucked
into the wind taken in by the product but is not being
discharged.
Noise sometimes gets louder because of the
influence of outdoor wind. This is not a malfunction.
Dew condensation water sometimes builds up in
some operating environments.
The volume of the noise sometimes differs, for
example, because of the length of the piping to each
room.
The product is operating in the supply air intermittent
mode.
The outdoor air temperature is low.
Small insects could intrude into the indoor from the
outdoor through the product.
If the outdoor temperature is low or the indoor
humidity is high, condensation can occur outside the
product.
Inside the product or the filters can become wet due
to fog outdoor or condensation.
If the outdoor or indoor humidity is high, condensation
can occur.
The air volume can increase/decrease automatically
if the product receives external output.
Cause
The Enable OFF button is set to invalid. (At factory
default settings, the Enable OFF button is set to No.)
Due to the skip setting.
(At factory default setting, the bypass ventilation is
set to Skipped.)
Due to the skip setting.
(At factory default setting,
To protect the Heat exchanger from frost in winter,
the air volume can increase/decrease.
The air volume can increase/decrease automatically
if the product receives external output.
When receiving the external input, the priority is
given to it even when the lower fan speed is selected.
(External input icon is displayed if the fan speed is
determined by the external input.)
Check the circuit breaker on the power board.
Press the
It is not a malfunction.
Re-install the filter. (see section 6.)
Clean the filter. (see section 6.)
Remove obstacles.
Clean the filter. (see section 6.)
Reduce the fan speed of the product.
The noise will disappear as it becomes easier to
discharge the dew condensation water in the drain
pipes.
If you are worried about sound fluctuation, contact your
dealer or an electrical contractor.
It is not a malfunction.
It is not a malfunction.
It is not a malfunction.
See Automatic supply air stop function/Automatic
supply air intermittent operation function. (see next
page.)
It is not a malfunction.
Supply air sometimes is cooled be the outdoor air.
It is not a malfunction.
The volume of intruding insects can be reduced by
using the high performance filter (optional parts).
It is not a malfunction.
Remove the condensation with a cloth.
It is not a malfunction.
It is not a malfunction.
Remove the condensation with a cloth.
It is not a malfunction.
Check the setting.
It is not a malfunction.
If the Enable OFF button is set, turn the isolator OFF to
stop the product.
To cancel the Enable OFF button setting, see 6.4.2.7
Control mode in the Installation Manual.
It is not a malfunction.
To cancel the skip setting, see 6.4.2.7 Control mode in
the Installation Manual.
It is not a malfunction.
is Skipped.) To cancel the skip setting, see 6.4.2.7 Control mode in
the Installation Manual.
It is not a malfunction.
It is not a malfunction.
Eng-19
Action
button on the controller to turn on.
Action