Troubleshooting 
Electrical Control  119 
d. Protection of pressure or temp. 
 
 
 
e. Open-circuit and short-circuit trouble of T3 
 
 
 
Is connection to connector of temp. sensor good? 
Check the resistance of the temp. sensor according to Appendix 1
Repair connector 
No 
Yes 
Is it the resistance is normal? 
Indoor PCB is defective. 
Replace the sensor 
Yes  No  
Protection of pressure or temp. 
Is it k1 or K2 open ? 
Is temp. protective switch K1 open 
Possible reason 
1.  The wires is loose to K1 
2.  Air or other gas in the refrigerant. 
3.  Heat exchanger is dirty 
4.  Outdoor fan or fan blade is 
defective 
5.  Outdoor unit is in bad ventilation 
Is pressure protective switch K2 open 
Yes 
Yes  Yes 
Possible reason 
1.  The wires is loose to K2 
2.  Air or other gas in the refrigerant. 
3.  Heat exchanger is dirty 
4.  Outdoor motor or fan blade is 
defective 
5.  Outdoor unit is in bad ventilation