Not sure why when I turn on my AC the unit comes on. When I flip it to heat, nothing happens. It worked the other night and I stayed warm. Woke up this morning freezing. Anyone have any ideas... suggestions?? I checked the breaker box and nothing was tripped. Thanks!

Perhaps there is a problem with the heating element. You'll probably have to have it repaired professionally.

Go to the sticky at https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html
Post back with what type of heating system you have and at what stage in the heat start up it fails. It may or may not be something we can help you fix.

Also, recheck your breakers. Sometimes they look OK, but need to be turned all the way to off and then back on.

Do you have gas heat or electric is it a heat pump? Give more info if you can.

Same thing happened to out on two different occasions. First a simple circuit breaker, next when the unit was close to 7 years old the ac was not cooling like it should. There was a leak and had to be sealed. After it was sealed we enjoyed the great cooling it did but guess what the sealant leaked to the heat valve and got it stuck (to ac mode only)wont witch to heat.