Cadillac Repair: Heater not working, cadillac catera, heater control valve

Question
1999 Cadillac catera, 6 cyl, light to medium mechanical abilities...
We had a mechanic verify the heater core was working. He "burped" the heatercore. We still can't get heat. I was told something about a heater control valve? Can you tell me what i'm looking for, what i'm supposed to find and what to check? It's getting in the low 30's and wife/kids aren't liking this vehicle right now.

Answer
First check the heater hoses where the enter into the firewall. One should be extremly HOT and the other slightly cooler.

You either have a:

restriction in the heater core or a fault in the AC/Heater programmer.

You will need pictures which are NOT allowed on this persons website and directives to test the programmer operation.

Please e-mail: onlineautohelp@msn.com for pictures and directives.