Toshiba MMU-UP0091H-E Installation Manual Download

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Periodic Maintenance

• For environmental conservation, it is strongly recommended that the indoor and outdoor units of the air

conditioner in use be cleaned and maintained regularly to ensure efficient operation of the air conditioner.
When the air conditioner is operated for a long time, periodic maintenance (once a year) is recommended.
Furthermore, regularly check the outdoor unit for rust and scratches, and remove them or apply rustproof
treatment, if necessary.
As a general rule, when an indoor unit is operated for 8 hours or more daily, clean the indoor unit and outdoor
unit at least once every 3 months. Ask a professional for this cleaning / maintenance work.
Such maintenance can extend the life of the product though it involves the owner’s expense.
Failure to clean the indoor and outdoor units regularly will result in poor performance, freezing, water leakage,
and even compressor failure.

Inspection before maintenance

Following inspection must be carried out by a qualified installer or qualified service person.

* Refer to the Service Manual for how to remove.

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Maintenance List

Parts

Inspection method

Heat exchanger*

Open the air intake grille to remove the bell mouth and the fan, and then check the heat exchanger

if there is any clogging or damages.

Fan motor

Check if any abnormal noise can be heard.

Fan

Open the air intake grille and check the fan if there are any waggles, damages or adhesive dust.

Filter

Open the air intake grille and check if there are any stains or breaks on the filter.

Drain pan*

Remove the panel, the bell mouth and the drain pan, and then check if there is any clogging,

abnormal smell or drain water pollution.

Part

Unit

Check (visual / auditory)

Maintenance

Heat exchanger

Indoor / outdoor

Dust / dirt clogging, scratches

Wash the heat exchanger when it is

clogged.

Fan motor

Indoor / outdoor

Sound

Take appropriate measures when

abnormal sound is generated.

Filter

Indoor

Dust / dirt, breakage

• Wash the filter with water when it is

contaminated.

• Replace it when it is damaged.

Fan

Indoor

• Vibration, balance
• Dust / dirt, appearance

• Replace the fan when vibration or

balance is terrible.

• Brush or wash the fan when it is

contaminated.

Air intake / discharge

grilles

Indoor / outdoor

Dust / dirt, scratches

Fix or replace them when they are

deformed or damaged.

Drain pan

Indoor

Dust / dirt clogging, drain

contamination

Clean the drain pan and check the

downward slope for smooth drainage.

Ceiling panel, louvers

Indoor

Dust / dirt, scratches

Wash them when they are contaminated

or apply repair coating.

Exterior

Outdoor

• Rust, peeling of insulator
• Peeling / lift of coat

Apply repair coating.

Troubleshooting



Confirmation and check

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Troubleshooting history and confirmation

You can check the troubleshooting history with the following procedure if a problem occurs with the air conditioner.
(The troubleshooting history records up to 4 incidents.)
You can check it during operation or when operation is stopped.
• If you check the troubleshooting history during OFF timer operation, the OFF timer will be cancelled.

If a problem occurs with the air
conditioner, the OFF timer indicator
alternately shows the check code and
the indoor Unit No. in which the
problem occurred.

Procedure

Description of operation

Push the OFF timer button for over 10 seconds

and the indicators appear as an image indicating

the troubleshooting history mode has been

entered. If [

Service check] is displayed, the

mode enters in the troubleshooting history mode.

• [01: Order of troubleshooting history] appears in the

temperature indicator.

• The OFF timer indicator alternately shows the [check

code] and the [indoor Unit No.] in which the problem
occurred.