My concord 80 plus gas furnace does not stay running even though the thermostat is calling for heat. The smart valve does 6 pulses when it goes into this mode. Could this be a thermocouple problem or should I look elsewhere?
Thanks

How old is your furnace Is it new enough to have a hot surface ignitor instead of a standing pilot. If so you also have a flame sensor. These flame sensors get corroded and neet to be cleaned. To find the ignitor look of a single wire post sticking up into the flame of opne of he burners. It will have only one wire going to it and it will be a ceramic post with the wire post sticking out of it. Take this loose by taking out one screw that holds it to the furnace. Now use a fine sand paper to clean the metal post, replace it and see if the furnace works.

Tried this procedure, 3 hours of running and no more problems! Thanks much didn't have the money to call repairman. People helping people!