I'm having a problem with my Concord gas furnace, in every cycle the exhaust fan comes on, then the igniter does it's job and lights all burners. However either one of two things happen afterwards: a) the burners suddenly go out, .... re-lights ...... goes back out,.... then repeats until the unit shuts down temporarily. (15-20 mins) ...... OR ..... b) Burners ignite and seconds later the blower comes on with-out any hesitation and heats the
house.
There is not routine to the cycle besides it is starting to happen much more often which is allowing the house temp to drop 10-12 degrees. Please, can anyone help me with this???

NorthernHeat

It sounds like a dirty flame sensor. Here is a post on cleaning it.
http://www.askmehelpdesk.com/heating...sor-57005.html