About a month ago I put in a new thermocoupler in my furnce and it's been working fine. This morning I woke up to no heat. I can re-light the pilot with no problems. The piot light keeps on burning if I don't turn the thermostat up to turn on the furnace. Then when I set the thermostat to 70 degrees the furnace comes on and runs for about 5 to 10 minutes and then shuts off before the house is to up 70 degrees (it's about 50 degrees in here since the furnace stopped running sometime overnight). When I check the pilot light, it is out again. In other words, the furnace and pilot are shutting off while the furnace is running. Is this a thermocoupler problem? Could I possibly have the wrong thermocoupler? Oh yeah, the filter is clean. Any suggestion are greatly appreciated. Thanks in advance for any help.

I would check to be sure the pilot orifice is clean. You should have cleaned that when you have the pilot/thermocouple assembly out for service.