54 Room Air Conditioner
Troubleshooting Guide
When Heating does not operate
Operate “Heating Mode( )” by setting the desired temperature of the
remote control is higher than one of the indoor temperature by 2°C at
least.
In heating Mode, the indoor fan operates in case the pipe temperature
is higher than 28°C.
Check the connector of intake and pipe sensor(thermistors)
• Check the related circuit of RY-4WAY
• Check the indoor room temperature is disconnected or not (about
10KΩ/at 25°C).
• Check the indoor pipe temperature is disconnected or not (about
5KΩ/at 25°C).
Turn ON Main Power
Check the DC voltage on the PWB ASSEMBLY
• The details of check are as followings
Check point
Between Micom
(NO.63) and GND
Between IC02M
(NO.14) and GND
Comp ON
DC 5V
Below DC 1V
Comp OFF
DC 0V
About DC
12V
Check point
Between Micom
(NO.51) and GND
Between IC03M
(No.9) and GND
4 way ON
DC 5V
Below DC1V
4 way OFF
DC 0V
About 12V
Check point
Between Micom
(NO.53) and GND
Between IC03M
(NO.11) and GND
Fan ON
DC 5V
Below DC 1V
Fan OFF
DC 0V
About DC 12V
• Comp Relay.
• 4 way Relay
• Outdoor fan Relay