We are having an issue with neither our heater or A/C working. The thermostat inside says that they are working. We have also tried to replace the thermostat and that didn't work either. We have also checked the breakers to make sure everything is fine there. What should we do next?

Fuse at the furnace switch, or fuse at the control board 3 amp car type, or maybe bad transformer.This are the first 3 places to check after you check the breaker. The transformer and the control board should be in the bottom door of your furnace.