Furnace - Amana GUIA115A40
Control board - White-Rodgers 50A50-298

My furnace just has the fans running non-stop and the control board is flashing an open limit switch error code. The furnace is getting good circulation and both fans seems to run fine.

I cut power to it all night, in the morning I turned on power and instantly got the open limit switch error code. This leads me to believe the open limit switch is faulty.

Just to be sure, is the open limit switch a quarter-sized "switch" with a blue dot on it and two wires coming off it just above the burners on the left on this particular model?

http://i85.photobucket.com/albums/k6...2/P1020854.jpg

Is the open limit switch the far left switch with the brown wires?
http://i85.photobucket.com/albums/k6...2/P1020858.jpg

Following the schematics, I found another auxiliary limit switch on the bottom (part# 10728317), jumpered that no change. I also jumpered the primary limit switch (shown above, part # 10728305) and it seems slightly different, the second fan took longer to come on like normal.

According to the schematics, the brown board (shown in the picture just to the left of the gas valve) is also an auxiliary limit. Can it be jumpered as well?

Did you tesgt the brown one with the 2 wires about 1 1 2 in by 3 in?

The brown one is your problem, tap it with a screw driver it will probably reset

Thank you Josh, just jumpered past that one and you are right, it's the brown one, fired right up. I was wrong about thinking the pictured one above was the primary limit, that's the rollout limit and tests fine.

I tried tapping it (a lot) and it stills shows no continuity, it's still open. I had read somewhere that the limit switches with the red buttons can be reset, the others are done once they pop?

This one is the part# 10728317. I assume they'll have it at any plumbing and heating store, but not Home Depot?

Right, you should be able to get that limit at any heating store. Just look on it to see what the temp is it will be marked L140 - 180