I have a new coleman furnace with a circuit board and the blower will not shut off after the burners cool off .. What will cause it to run all the time and not shut off. Gene

Hi Gene. Since your furnace is new contact the company that sold you the unit and did the install. messing with a new furnace while under warenty is a NO NO and can cause the warrenty to be voided by the manufacturer. All warrenty work has to be done by the Coleman dealer as per the warrenty papers that came with your unit. Within the first year free parts and usually the labor is covered also.

are you saying that blower will not shut off ever, or it just takes a long time before it shuts off? There are some dip switches on the board that will change blower on and off times, but i would do as hvac suggested and have the original installer back to adjust them. If you set them incorrectly, it may cuase other problems(high limit, etc)

Did you install this yourself, or did you have it done professionally?. If you did it yourself, you are pretty much screwed as far as warranty goes, but we may be able to help. If it was pro installed, then they should come back and take care of your problem. Please let us know if you want further help, and either way, please let us know what you find.