Hi ! With the 737 i started with a save panel state as long flight. All the checklists were respcted as usuall. After engine start only on the copilot side there were the air cond sign on. i will show u some screen so that u can try to see and understand what can be the possible problem. Packs were on after engine start bleed air as well altitude was set in the over head same like landint altitude. this is the first time i see this problem over 1500 of flights with this plane..

 

Thanks everyone

 

here are the links to see the screenshots 

 

http://www.picpaste.com/cruise-JoFRlE4k.jpg

 

http://www.picpaste.com/overhead-bcM1LbaK.jpg

did you ac tually climb to the cruise altitude that you set on overhead? If you did, then I'm stumped, if you didn't and descend, you get that warning.

i get that warning on the ground after starting engines. Climbing at cruise altitude i was at FL350 it didnt change the situation the light was always on. 

Do you see yellow sign on the overhead "zone temp" just above temp regulators?

It's a warning sign. And if you see a warning sign all you have to do is check QRH. In our case it's page 90 of pdf file. There is a checklist which you have to do and you are all set.

Sometimes I get this warning when flying from airport with hot weather, but you can also check failures menu in CDU.