Does anyone know what I can do? My carrier heater is only 2 years old. As of yesterday the heater unit wouldn't shut off and when I turn the heat up it just keeps blowing cool air. I heard I can trip a breaker switch. Is that the electrical switch in the garage or on the heater itself? Please let me know what this issue is! Thank you!

There should be a breaker in the main electric panel that will turn off the unit. There could be more than one breaker.

It would be best for you to call for service to get it fixed.