Often the cause of the failure of air conditioner can be determined by description. The use by Actron air error codes makes it easier. The table with codes below will be a good manual and can help to identify the cause of failure and a way to solve the problem on your own, without calling the repairman.
|E3||System has detected less than 2 sensors||(Ultima requires at least 2 sensors in circuit) or, a remote sensor is short circuit|
|E5||No Communication||The system is constantly relaying information back and forth. This indicates the communication is not happening. Contact your installer to check your wiring and cable’s integrity|