Toshiba MML-UP0071H-E, Installation Manual

– 21 –

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.

Maintenance List

Parts

Inspection method

Heat exchanger

Access from inspection opening and remove the access panel. Examine the heat 

exchanger if there is any clogging or damages.

Fan motor

Access from inspection opening and check if any abnormal noise can be heard.

Fan

Access from inspection opening and remove the access panel. Examine the fan if there 

are any waggles, damages or adhesive dust.

Filter

Go to installed location and check if there are any stains or breaks on the filter.

Drain pan

Access from inspection opening and remove the access panel. Check if there is any 

clogging or drain water is polluted.

Parts

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, louvres

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.

12

Troubleshooting



Confirmation and check



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 canceled. 

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

1

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. 

2

Each time the setting button is pushed, the recorded 

troubleshooting history is displayed in sequence.
The troubleshooting history appears in order from [01] 

(newest) to [04] (oldest).

CAUTION

CAUTION

In the troubleshooting history mode, DO NOT push 
the Menu button for over 10 seconds, doing so 
deletes the entire troubleshooting history of the 
indoor unit.

3

After you have finished checking, push the ON/OFF 

button to return to the regular mode.
•  If the air conditioner is operating, it remains operated 

even after the ON/OFF button has been pushed. 
To stop its operation, push the ON/OFF button again.

Check code

The indoor Unit No. in which

the problem occurred.

3

1

2

41-EN

42-EN