Furnace Question
 

We have a Trane XB80 that was last serviced about a year ago and needed the blower (i think) replaced. Since then it has been working like a champ but today we noticed that the furnace was continuously running. I checked the vents and they are blowing cool air. I went to the thermostat (Honeywell RTH8500D) and the heat wasn't turned on but after turning up the temp the heat kicked in. after this I turned the thermostat off but the furnace continues to run.

Since this I have replaced the air filter and turned the furnace off at the fuse box for about 30 minutes yet it still is running.

So, any thoughts? Should I just call a service tech or do any of you have any suggestions on how I can trouble shoot this? Thanks in advance.

Some furnaces are designed to always run, keeps air circulating through the house and moisture down. You can wire your furnace to not do this if you choose.