Just ran into problem where the furnace won't start. The blower is just blowing cold air. Found red ling doing one blink. Searching the internet says their is problem with the limit circuit. I turned off the power and verified with a multimeter that the circuit is closed between the flame rollout switches and the limit switch. There is another switch on this circuit that is open. I'm not sure how to get to it. It goes down into the lower blower compartment and then to the back behind the blower. Any ideas what this switch is or how to get to it? It looks like I could take out a bizzilion screws on the back panel maybe? Any help would be appeciated. Also, is it safe to wire the limit circuit closed for a night or two?

 

Many multi-position furance have a limit switch on or near the blower. Often removal of the blower is needed to get to the switch.

 

Grady, Thanks for the help. The broken limit switch was behind the blower. It took a little work to figure out how to remove the blower unit. It wasn't too bad. I removed the limit switch and was able to read the part number off the side of it. I ordered a new one and installed it today. Everything is back up and working! Thanks again for your help.

 

Glad I was able to help. I just love it when manufacturers 'hide' things like limit switches. NOT!!