I just recently moved into place with a coleman heatpump model EB15B. I woke up next morning and the heat was on all night. I tried changing the thermostat but still same results. I thought maybe it was contactor in outside unit but it does not run continuously. What could it be and can I fix it?

OK so if outside unit doesn`t runn all the time ,the problem has to be the furnace/airhandler
Remove the red (hot low voltage wire) that goes to the tstat from furnace,, does it keep running? this will rule out the posible pinched or shorted tstat wire., if you have a gas burnace does it have a blinking light if so count the blinks and look on inside of door/cover it should tell you what the codes are.
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