I had my furnace limit switch go out a year ago and had a service tech replace it. Last week the same thing happened, i am told it was because I had a dirty filter(which I probably did, I am doing some drywalling, sanding etc in my house, lots of white dust). I replaced the limit switch again and things are going fine. I decided to get a spare limit switch, since they are $10, in case this happens again. My problem is when I called the only parts place I can get parts from, they tell my I have the wrong limit switch in my furnance. I am confused because the last switch put in my furnace was put in by a professional. I have a Carrier 9200 weathermaker, model#= 58MXA080 14116. Pro put in a HH12ZB220(220 deg) and the parts guys says I need a HH12ZB250(250 Deg). I am alittle worried about putting a 250 limit in, if the pro is correct with the 220 limit switch. Would my furnace be more efficient with a 250 switch? What should I do?
You need the correct sized switch or the heat exchanger can be seriously damaged if it is the higher one. Need to contact another Carrier supplier and find out. Should not be blowing those switches as they are fairly high temp ones. Check the underside of your AC coil for blockage and clean the fan and make sure all your vents are clean and open.
Read this post and check the temp rise:High Limit Switch Question
"Cut it twice and it is still too short".