My electric furnace was kicking the breaker and shutting down. I'd reset and it would work fina a week oe two then blow it again. Now it won't shut down. Is this a thermostat problem or something else.

Could be a thermostat BUT I would check the heat relays or what ever controls turning the heaters on and off inside the electric furnace.

Sounds like a relay or control is stuck shut allowing low voltage or high voltage to stay on all the time.

hvac1000 is 100% correct on his answer... electric heater have two controls, a relay and a time delay sequencer to stage the strip heater to come on a different times to spread the electrical load on start up... the heater could be stuck on, and if you have a fan failure, you could have a over heated unit and possible fire condition. ( you would have no fan operation to cool the unit as the electric heater element continues to run ) As well, the HVAC tech should check the amp draw on each electric heater to see if one is going bad, causing the breaker to trip... another cause of the breaker to trip, is a bad electrical element going to ground.