Could be the circuit breaker itself is weak.
The old unit may have drawn less amps.

Could be that the heating element is grounded.
This may have happened when you moved the unit.
Check that the unit cycles on different heat settings.
Check the heating coil.
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 10 to12 ohms.
Then check from each side of the coil to the case/frame, both should be infinite ohms (open). If not the coil may have sagged or broken and is touching the case (grounded). This can cause it to run on high and the thermostats cannot regulate it.

You are welcome

And thanks for getting back to us. Now when others search for a similar problem they will see what actually worked instead of just suggestions about what could be the cause.