The blower comes on when the furnace is not calling for heat

Possible defective fan and limit control or blower control disc. This answer is posted for a gas furnace.

Could be that the tstat is set for fan and not on auto


I hate having to give this answer,, but I have had to go on service calls several times and this is all that is wrong with the system,, I feel bad about having to charge them but,, my time, and truck can`t run for nothing