DOWNLOAD Panasonic CS-TZ20TKEW / CS-TZ25TKEW / CS-TZ35TKEW / CS-TZ42TKEW / CS-MTZ16TKE / CU-TZ20TKE / CU-TZ25TKE / CU-TZ35TKE / CU-TZ42TKE Service Manual ↓ Size: 23.23 MB | Pages: 127 in PDF or view online for FREE

93 

In order to diagnose malfunctions, make sure that there are no 
electrical problems before inspecting the refrigeration cycle. 
Such problems include insufficient insulation, problem with the 
power source, malfunction of a compressor and a fan. 
The normal outlet air temperature and pressure of the refrigeration 
cycle depends on various conditions, the standard values for them 
are shown in the table on the right. 
 
 
 
 

 

 
 
 
 
 

Normal Pressure and Outlet Air Temperature (Standard)

 

Gas Pressure 

MPa 

(kg/cm

2

G) 

Outlet air 

Temperature 

(°C) 

Cooling Mode

0.9 ~ 1.2 (9 ~ 12) 

13 ~ 17 

Heating Mode 2.0 ~ 2.7 (20 ~ 27) 

32 ~ 42 

*Condition:  • Indoor fan speed = High 

• Outdoor temperature 35°C at the cooling 

                      mode and 7°C at the heating mode 
                    • Compressor operates at rated frequency       

94 

 

Condition of the  

air conditioner 

Cooling Mode 

Heating Mode 

Low Pressure 

High Pressure 

Electric current 

during operation

Low Pressure 

High Pressure 

Electric current 

during operation

Insufficient refrigerant 

(gas leakage) 



 



 



 



 



 



 

Clogged capillary tube or 

Strainer 



 



 



 



 



 



 

Short circuit in the indoor unit 



 



 



 



 



 



 

Heat radiation deficiency 

of the outdoor unit 



 



 



 



 



 



 

Inefficient compression 



 



 



 



 



 



 

•  Carry out the measurement of pressure, electric current, and temperature fifteen minutes after an operation is started. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

95 

  Once abnormality has occurred during operation, 

the unit will stop its operation, and Timer LED 
blinks. 

  Although Timer LED goes off when power supply 

is turned off, if the unit is operated under a 
breakdown condition, the LED will light up again. 

  In operation after breakdown repair, the Timer 

LED will no more blink. The last error code 
(abnormality) will be stored in IC memory. 

1  Timer LED start to blink and the unit 

automatically stops the operation. 

2  Press the CHECK button on the remote 

controller continuously for 5 seconds. 

3  “- -” will be displayed on the remote controller 

display. 
Note: Display only for “- -”. (No transmitting 
signal, no receiving sound and no Power LED 
blinking.) 

4  Press the “TIMER” ▲ or ▼ button on the 

remote controller. The code “H00” (no 
abnormality) will be displayed and signal will 
be transmitted to the main unit. 

5  Every press of the button (up or down) will 

increase abnormality numbers and transmit 
abnormality code signal to the main unit. 

6  When the latest abnormality code on the main 

unit and code transmitted from the remote 
controller are matched, power LED will light 
up for 30 seconds and a beep sound 
(continuously for 4 seconds) will be heard. If 
no codes are matched, power LED will light up 
for 0.5 seconds and no sound will be heard. 

7  The breakdown diagnosis mode will be 

canceled unless pressing the CHECK button 
continuously for 5 seconds or operating the 
unit for 30 seconds. 

8  The LED will be off if the unit is turned off or 

the RESET button on the main unit is pressed. 

1  Turn power on. 
2  Press the CHECK button on the remote 

controller continuously for 5 seconds. 

3  “- -” will be displayed on the remote controller 

display. 
Note: Display only for “- -”. (No transmitting 
signal, no receiving sound and no Power LED 
blinking.) 

4  Press the “TIMER” ▲ or ▼ button on the 

remote controller. The code “H00” (no 
abnormality) will be displayed and signal will 
be transmitted to the main unit. The power 
LED lights up. If no abnormality is stored in 
the memory, three beeps sound will be heard. 

5  Every press of the button (up or down) will 

increase abnormality numbers and transmit 
abnormality code signal to the main unit. 

6  When the latest abnormality code on the main 

unit and code transmitted from the remote 
controller are matched, power LED will light 
up for 30 seconds and a beep sound 
(continuously for 4 seconds) will be heard. If 
no codes are matched, power LED will light up 
for 0.5 seconds and no sound will be heard. 

7  The breakdown diagnosis mode will be 

canceled unless pressing the CHECK button 
continuously for 5 seconds or operating the 
unit for 30 seconds. 

8  The same diagnosis can be repeated by 

turning power on again. 

 

“Check” button

 

 

1  Turn power on (in standby condition). 
2  Press the AUTO button for 5 seconds (A beep 

receiving sound) on the main unit to operate 
the unit at Forced Cooling Operation modes. 

3  Press the CHECK button on the remote 

controller for about 1 second with a pointed 
object to transmit signal to main unit. A beep 
sound is heard from main unit and the data is 
cleared. 

1  Press the AUTO button (A beep receiving 

sound) on the main unit to operate the unit. 
(Remote control will become possible.) 

2  The unit can temporarily be used until 

repaired. 

 
 
 
 
 
 
 

96 

H00 

No memory of failure 

— 

Normal operation

— 

— 

H11 

Indoor/outdoor 
abnormal 
communication 

After operation for 
1 minute 

Indoor fan only 
operation can 
start by entering 
into force cooling
operation 

Indoor/outdoor 
communication not 
establish 

 Indoor/outdoor wire terminal 

 Indoor/outdoor PCB 
 Indoor/outdoor connection wire 

H12 

Indoor unit capacity 
unmatched 

90s after power 
supply 

— 

Total indoor capability 
more than maximum limit 
or less than minimum limit, 
or number of indoor unit 
less than two 

 Indoor/outdoor connection wire 
 Indoor/outdoor PCB 

  Specification and combination 

table in catalogue 

H14 

Indoor intake air 
temperature sensor 
abnormality 

Continuous for 5s 

— 

Indoor intake air 
temperature sensor open 
or short circuit 

  Indoor intake air temperature 

sensor lead wire and connector 

H15 

Compressor 
temperature sensor 
abnormality 

Continuous for 5s 

— 

Compressor temperature 
sensor open or short circuit

 Compressor temperature 

sensor lead wire and connector 

H16 

Outdoor current 
transformer (CT) 
abnormality 

— — 

Current transformer faulty 
or compressor faulty 

  Outdoor PCB faulty or 

compressor faulty 

H19 

Indoor fan motor 
merchanism lock 

Continuous 
happen for 7 times 

— 

Indoor fan motor lock or 
feedback abnormal 

  Fan motor lead wire and 

connector 

  Fan motor lock or block 

H23 

Indoor heat 
exchanger 
temperature sensor 
abnormality 

Continuous for 5s 

— 

Indoor heat exchanger 
temperature sensor open 
or short circuit 

  Indoor heat exchanger 

temperature sensor lead wire 
and connector 

H24 

Indoor heat 
exchanger 
temperature sensor 
2 abnormality 

Continuous for 5s 

— 

Indoor heat exchanger 
temperature sensor 2 open
or short circuit 

  Indoor heat exchanger 

temperature sensor 2 lead wire 
and connector 

H25 

Indoor ion device 
abnormality 

Port is ON for 10s 
during ion device off 

— — 

  ion device PCB 

H27 

Outdoor air 
temperature sensor 
abnormality 

Continuous for 5s 

— 

Outdoor air temperature 
sensor open or short circuit

  Outdoor air temperature sensor 

lead wire and connector 

H28 

Outdoor heat 
exchanger 
temperature sensor 
1 abnormality 

Continuous for 5s 

— 

Outdoor heat exchanger 
temperature sensor 1 open
or short circuit 

  Outdoor heat exchanger 

temperature sensor 1 lead wire 
and connector 

H30 

Outdoor discharge 
pipe temperature 
sensor abnormality 

Continuous for 5s 

— 

Outdoor discharge pipe 
temperature sensor open 
or short circuit 

  Outdoor discharge pipe 

temperature sensor lead wire 
and connector 

H32 

Outdoor heat 
exchanger 
temperature sensor 
2 abnormality 

Continuous for 5s 

— 

Outdoor heat exchanger 
temperature sensor 2 open
or short circuit 

  Outdoor heat exchanger 

temperature sensor 2 lead wire 
and connector 

H33 

Indoor / outdoor 
misconnection 
abnormality 

— — 

Indoor and outdoor rated 
voltage different 

  Indoor and outdoor units check 

H34 

Outdoor heat sink 
temperature sensor 
abnormality 

Continuous for 2s 

— 

Outdoor heat sink 
temperature sensor open 
or short circuit 

  Outdoor heat sink sensor 

H36 

Outdoor gas pipe 
temperature sensor 
abnormality 

Continuous for 5s 

Heating 
protection 
operation only 

Outdoor gas pipe 
temperature sensor open 
or short circuit 

  Outdoor gas pipe temperature 

sensor lead wire and connector 

H37 

Outdoor liquid pipe 
temperature sensor 
abnormality 

Continuous for 5s 

Cooling 
protection 
operation only 

Outdoor liquid pipe 
temperature sensor open 
or short circuit 

  Outdoor liquid pipe temperature 

sensor lead wire and connector 

H38 

Indoor/Outdoor 
mismatch (brand 
code) 

— 

— 

Brand code not match 

  Check indoor unit and outdoor 

unit 

H39 

Abnormal indoor 
operating unit or 
standby units 

3 times happen 
within 40 minutes 

— 

Wrong wiring and 
connecting pipe, expansion 
valve abnormality, indoor 
heat exchanger sensor 
open circuit 

 Check indoor/outdoor 

connection wire and connection 
pipe 

  Indoor heat exchanger sensor 

lead wire and connector 

  Expansion valve and lead wire 

and connector