I have a ENVIROMASTERS CLC42D711AA0A0B 3-1/2 TON A/C MINI SPLIT 208/230 VOLT R22 50645. It blows warmish cool air, not cold air. Any idea what is the problem? What is the first thing I need to check?

The first thing to check would be the charge of the system, however, this is only to be done by a tech with a refrigerants license. Almost all mini splits have flared connections, and most times they are the source of a leak. If there is indeed a leak, most newer mini splits will not allow the compressor to run if the system is low on refrigerant. So your first step is to call a tech in to diagnose and fix the issue. Good luck, and please do let me know what is found.

PS. Also, many mini splits only have one port to hook your guages to, so if the system has lost refrigerant, the only way to correctly charge it is to reclaim any refrigerant left in the system, vacuum the system, then recharge by factory charged weights ( of course after you have found and fixed the leak). Hope this helps.