Thank you very much. You are right on the money. It was a spider web and spider in the orfice tube. Cleaned it out and everything is working perfect.y. I have a 110 degrees coming out of the registers.

Thanks again.

Hi, I am working on a Pres II model 7663B 856 series. When the thermostate is engaged the burner comes on and the unit heats up, the blower comes on and runs for about a minute and then shuts off. The burner remains on. After a while about 6 minutes the blower comes on a runs for a minute and then s...