I have a Samsung Air Conditioner model AQV12MSAN.

Recently I encounter the following problem:
When opperates in Heat Mode and adjusted temperature less than 22C - the Air Conditioner turns off itself and displays E2-37 or E4-16 at the display panel (First E2 - then 37, First E4 then 16).

Could you tell me please what these errors means.

Thank you in advance for your help.