The furnace is an electric intertherm.Last night the blower continued to run even though the heating elements had stopped and never did shut off.The only way to get it shut off is to turn off the breaker.The switch is set to auto on the fan.The furnace works fine,the blower for some reason has decided to not shut down when thermostat reaches temp.Ican look in and see that the heating elements are not on while the fans on.I did replace the thermostat hoping that was the problem and it didn't help,same problem.Not sure if this matters but there are only two wires to the thermostat.Anyone have a clue what's wrong and what happened?tia

The blower is switched on and off by a relay. The coil of the relay is usually activated by a limit switch. The limit switch will be near the heating elements and have 2 wires going to it. There should be a second one too that shuts the heating elements off if they get too hot because the blower didn't start or something.

Do your best to find the limit switch and make sure it is working. Usually the relay sticking is the problem, but often they are on a circuit board and a pain to diagnose and replace without paying big bucks for a whole, new circuit board.