24
YES
NO
YES
(24 Volt)
Check voltage between terminals No. 1
(+) and No. 2 at four poles connector
(DC 24V). (Unit connector)
Indoor controller Ass’y is defective.
(PCB1).
(0 Volt)
No voltage appears.
Defrost controller Ass’y is defective.
(PCB2).
(7) CHECK PCB ASS’Y IN INDOOR UNIT (HEAT PUMP MODEL)
POOR COOLING OR POOR HEATING
Check position of remote control
unit.
Cool or warm air from air conditioner
reaches position directly.
Are wide and narrow tubes between
indoor unit and outdoor unit insulated?
Is fan speed set to LOW?
Measure temperatures of suction
and discharge air of air conditioner.
Review cooling or heating load esti-
mate, if performance of air conditio-
ner is normal.
Air filter is clogged.
Change position of remote control
unit.
Insultate wide and narrow tubes and
then tape together.
Set fan speed to either high or
medium.
Charge refrigerant gas (R22).
Reduce cooling or heating load or
replace unit with larger capacity.
Clean filter
Possibility of gas shortage?
Temperature difference between suction and discharge
air is large enough (approx. 10 °C. or more).
SI
YES
EXCESSIVE COOLING OR HEATING
Remote control unit is placed where
it can detecf room temperature pro-
perly.
Change position of remote control
unit.
G
H
