I have a Duo therm electric furnace that wants to run all the time. Ive replaced the thermostat and that didn't help, The last thing I tried was completely disconecting the thermostat, it just for heat, two wires and there just hanging out of the wall and the furnace still runs and won't shut off... Anyone have any idea as to what is wrong with it? Please help. Thanks, Rick

I would highly recommend calling a furnace repair company on this before you try to diagnose the problem yourself and wind up getting the shock of your life from touching the wrong wire or worse. Electric furnaces are generally not something an amateur should monkey around with unlike a dishwasher or refrigerator due to the high voltage they pack. Call several service companies and ask what their service call charge is and go with the company you feel most comfortable with. It could be something very simple to change out but not knowing which component is going bad or is bad could cost you your life.

Your sequencer/heat relay is defective and failed in the closed position causing the heater(s) to stay energised in the operative mode without the need of a thermostat signal.

Replace defective part(s)

This is a 30 yr old duo therm model 301050-001 heater only. Don't you think that If the breaker is off and the other circuts at the furnace are off that its safe enough to remove the sequincer? Also, I have the wiring diagram on the inside of the panel . Do you know who would carry a replacement for that, and ids the heat relay another part entirely? Thanks, Rick

No original parts are available to the best of my knowledge.

The defective part will have to be a substitute and the wiring will probably have to be changed to make it work.

When all power to the unit is turned off the power should be off BUT I always test to make sure because a circuit breaker can hang especially Federal Pacific brand.

This might be better left to a HVAC service person. If not and you mess it up it will cost you moke to fix it.