I have a Day and Night Furnace that is about 15 years old. It works fine and is producing heat but the BLOWER seems to be stuck and runs constantly. Friends tell me that it could be the Blower Relay or a bad thermostat. Is the blower relay something I can change myself? There is a schematic on the inside panel of my unit. Is this an expensive repair?

Is it likely that this is the cause of the problem?

I have no idera how much it will cost you to repair since the prices are different all over the USA. The problem is in the fan and limit control circuit. It could be a sensor or the circuit board.

I did not intend to disagree with the gentleman that answered this question! My APOLOGIES! I could not find a way to delete it. I think he's right! I DID NOT MEAN to disagree with him.

There is no diagreement here. I told you that

The problem is in the fan and limit control circuit. It could be a sensor or the circuit board

Now I told you what the problem is I can do no more since I am not there to fix it. LOL

Since no exact model number was posted you were given the best guess answer possible. I do not have a crystal ball.

just a small possibility,,,,have you made sure the thermostat is set on auto and not on fan ? won`t be the first time it has happened