I called Action Air Conditioning, Heating & Solar to check out my air conditioning unit. They put in a fan there that was supposed to distribute air more efficiently. What it did was disconnect the thermostat. I wasn't able to set the thermostat anymore, I had to physically turn the air conditioner on and off. I called them to ask them to return and take that fan out. They said they would charge me extra. Finally, they did come back and took the fan out after I insisted. As soon as they did the thermostat worked.