Is cold water discharged for
more than 3 minutes ?
START
Operation mode change
to Heating mode
Operate the unit in heating mode.
Does Test operation start?
Check whether the power cable and 
communication cable are completely connected
Yes
No
Yes
No
Is hot water discharged ?
Yes
No
Is there any temperature 
difference between intake and 
discharged water?  
No
Yes
Normal
* Check the load (In/Out Temp.)
* Check pipe length and amount of
   refrigerant 
* Check for abnormal sound in 
* Refer to Troubleshooting Guide 
  outdoor unit (comp.,Fan, others )