We have a Goodman unit, model:1999 cpkj30-1ab, serial: 990356219.

The problem is, I turned the unit "OFF" and woke to find hot air coming though the vents. The wall thermo is still to the OFF setting. It's like the heat is stuck. I had to go to the main power box and turn it off. What could be the problem?

If disconnecting heat wire or fan wire from the thermostat does not turn it off, it is not the thermostat. Short in control wires or stuck relay?

Is this a electric furnace?

Is this a electric furnace?

Yes

Odds are you have a stuck sequencer probably will need replaced but you can tap them with the power turned off and see if it go off.

http://www.drillspot.com/pimages/63/6339_300.jpg

If disconnecting heat wire or fan wire from the thermostat does not turn it off, it is not the thermostat. Short in control wires or stuck relay?

What color is the heat wire,and what is the fan wire?