Hitachi RAC-25YH4, Service Manual, Page: 25 / 121

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REGULAR INSPECTION
PLEASE CHECK THE FOLLOWING POINTS EVERY EITHER HALF YEARLY OR YEARLY. CONTACT
YOUR SALES AGENT SHOULD YOU NEED ANY HELP.
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2
3
WARNING
WARNING
Check to see if the unit’s earth line has been con-
nected correctly.
If the earth line is disconnected or faulty, unit failure or
electric shock hazard may result.
Check to see if the mounting frame has rusted ex-
cessively or if the outdoor unit has tilted or become
unstable.
It could collapse or fall, causing injury.
AFTER SALES SERVICE AND WARRANTY
WHEN ASKING FOR SERVICE, CHECK THE FOLLOWING POINTS.
CONDITION CHECK THE FOLLOWING POINTS
• Do the batteries need replacement?
• Is the polarity of the inserted batteries correct?
• Is the fuse all right?
• Is the voltage extremely high or low?
• Is the circuit breaker “ON”?
• Is the power plug inserted?
• Do you have any power cut?
• Is the air filter blocked with dust?
• Is the set temperature suitable?
• Have horizontal air deflectors been adjusted to their correct
positions according to the operation mode selected?
• Are the air inlets or air outlets of indoor and outdoor units
blocked?
• Is the fan speed “LOW”?
When it does not operate.
When it does not cool well.
When it does not heat well.
If the remote controller is not
transmitting a signal.
(Remote controller display is
dim or blank.)
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The following phenomena do not indicate unit failure.
<Operation start>
The unit is preparing to blow warm air. Please wait.
<In operation>
The outdoor unit is defrosting. Please wait.
Refrigerant flow noise in the pipe or valve sound generated when flow rate is
adjusted.
Noise generated when the unit expands or contracts due to temperature changes.
Noise generated with the indoor unit fan’s rpm changing such as operation start
times.
Noise of the motorized valve when the unit is switched on.
During heating, the operation
indicator blinks and air blow stops
Hissing or fizzy sounds
Squeaking noise
Rustling noise
WARNING
Clicking noise
Check to see if the power plug is securely inserted
into the wall socket.
If the power plug is not inserted into the wall socket
securely or becomes hot, an electric shock or fire may result.
If dust or dirt is found on the power plug, clean the plug
and insert it into the wall socket.
RAS_25_35_AW_001-024 2003.12.31, 10:45 AM 23