When The Following Symptoms Are Found; Heating - Toshiba MMU-UP0091H-E Owner's Manual

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Cleaning the indoor unit and
remote controller
• Ask Qualified service person to clean the indoor
units for the models listed in the warning on the top
of this chapter.
• Wipe with a dry, soft cloth.
Do not use acidic or alkaline detergents.
• If heavily stained, wipe off dirt with a cloth soaked in
lukewarm water.
(Do not use water to wipe the remote controller)
• Do not use benzine, thinner, scouring powder,
chemical cloth, etc. as those may cause deformation
or breakage.
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If unused for over a month
• Leave the fan on for half a day or so to dry the inside.
• Turn off the main power switch.
• Clean the air filter and then attach it.
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Periodic inspection
• After being used for a long period of time, the parts
may deteriorate or malfunction, or the drainage may
worsen, due to heat, moisture, dust, or general
usage.
• In addition to the maintenance, it is recommended
that you have a inspection (charges apply)
performed by the dealer where you purchased the
unit, etc.
CAUTION CAUTION
Perform high-pressure cleaning for the heat
exchanger.
If commercially available detergent (strong alkaline or
acid cleaning agent) is used, the surface treatment of the
heat exchanger will deteriorate, which may degrade the
self cleaning performance. For details, contact our sales
department or the dealer where you purchased the unit.
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Before the cooling season
Ask a Qualified service person to clean the drain
pan.
CAUTION CAUTION
Clean the drain pan.
Without cleaning, the drain pan may be filled with waste,
and water may overflow onto the ceiling or floor.
If you do not plan to use the unit for more
than 1 month
1. Operate "Fan" mode.
Run the fan for about half a
day to dry the inside fully.
2. Stop the air conditioner and
turn off the main power
switch.
Checks before operation
1. Check that the air filters are installed.
2. Check that the air discharge or intake is not blocked.
3. Turn on the main power switch.
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When the following symptoms are found

Check the points described below before asking repair servicing.
Symptom
• White misty cold air or water is out.
Outdoor unit
• Sometimes, noise of air leak is heard.
• "Swish" sound is heard sometimes.
• Slight clacking sound is heard.
• Discharge air smells.
Indoor unit
• " " indication is lit.
• " " indication is lit.
• Sound or cool air is output from the stand by
indoor unit.
• When power of the air conditioner is turned on, "Tick-tock"
sound is heard.
• LCD blurs when it is touched.
• Fan and louvres of the indoor unit moves when the unit is not
operated.
Stops automatically.
Does not operate.
Air is not cooled or warmed sufficiently.
CAUTION CAUTION
If any of the following conditions occur, turn off the main power supply switch and immediately contact the dealer:
• Switch operation does not work properly.
• The main power fuse often blows out, or the circuit breaker is often activated.
• A foreign matter or water fall inside the air conditioner.
• When the air conditioner does not operate even after the cause of the protective device activation has been removed.
• Any other unusual conditions are observed.
– 12 –
Cause
• Fan of the outdoor unit stops automatically and performs
defrost operation.
• Solenoid valve works when defrost operation starts or finishes.
• When the operation has started, during the operation, or
immediately after the operation has stopped, a sound such as
water flows may be heard, and the operation sound may
become larger for 2 or 3 minutes immediately after the
operation has started.
They are flowing sound of refrigerant or draining sound of
dehumidifier.
• This is sound generated when heat exchanger, etc. expand
and contract slightly due to change of temperature.
• Various smell such as one of wall, carpet, clothes, cigarette, or
cosmetics adhere to the air conditioner.
• When cooling operation cannot be performed because another
indoor unit performs heating operation.
• When stopping the fan to prevent cool air blow at starting

heating.

• Since refrigerant is flowed temporarily to prevent stay of oil or
refrigerant in the stand by indoor unit, sound of flowing
refrigerant, may be heard or white steam when other indoor
unit operates in Heat mode, and cold air in Cool mode may be
blow-out.
• Sound is generated when the expansion valve operates when
power has been turned on.
• LCD may temporarily blur by static electricity.
• Intermittent operation of the fan with louvres open is sometimes
carried out for the refrigerant recovery control of unoperated
unit.
• Is the timer "OFF"?
• Is it a power failure?
• Is the power switch turned off?
• Is the power fuse or breaker blown?
• Has the protective device operated? (The operation lamp goes
on.)
• Is the timer "ON"? (The operation lamp goes on.)
• Are Cool and Heat selected simultaneously?
(" " indication is lit on the display of the remote controller.)
• Is outdoor temperature out of operation temperature range?
• Is the air intake or air discharge of the outdoor unit obstructed?
• Are any door or window open?
• Is the air filter clogged with dust?
• Is discharge louvre of the indoor unit set at appropriate
position?
• Is air selection set to "Low" "Med.", and is the operation mode
set to "Fan"?
• Is the setup temp. the appropriate temperature?
• Are Cool and Heat selected simultaneously?
(" " indication is lit on the display of the remote controller.)
• Is outdoor temperature out of operation temperature range?
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