Why is my home air conditioning blowing hot and cold air?
Question:I attempted to change my thermostat at home. After an unsuccesful try, I put the old one back on. I'm pretty sure I put the wires back correctly, but now its randomly blowing hot air and cold air at different times. Appreciate your responses.
Answers:
Go to the indoor air handler (the furnace part of the air conditioner system). Open the front panel and look for the thermostat wire. It will be attached to a board or terminal block, or it could be wire-nutted to other wires.
The wires are color coded. Most times, the colors control the following (this is subject to change, depending on who wired the unit and the manufacturer).
R Red = power, 27v AC
G Green = fan
Y Yellow = first or single stage cooling
W White = first stage heating
O Orange = reversing valve on heat pump
C blue or black = common power, 27v AC
There may be other colors and numbers of letters. If there are, and there are wires attached, write down what wire is attached to what terminal. If you don't have terminals, call a pro.
Return to your thermostat. verify that the wires attached at the unit are attached to the same terminals in the thermostat.
The way a thermostat works, is say you like your home to be 70 degrees (F). When the thermostat senses 72 degrees, it tells the fan to come on, and the condenser to come on. The fan and and the condenser take the warm air in your home, remove the heat, and return cool air to the home. The air leaving the air handler will be 20* cooler than the air going in. When the air around the thermostat reaches 69.5 degrees, it tells the compressor to stop. The fan may continue running for a minute or two to bring the evaporator up to room temperature. Five minutes later, the air around the thermostat has warmed up to 72 degrees. The thermostat calls the fan and compressor to come on, but the compressor has another controller that prevents it from operating unless it has rested for 10 minutes. The fan is running, and the air is warming up. The fan motor is producing heat, and the air is blowing, but the heat is not being removed. After the rest period has ended, the compressor starts up again, and the heat is removed from the house.
Does this sound like what is happening to your system?
I'm guessing it's broken. You might want to check with an actual expert on heating and cooling. It's really going to suck if your AC unit is blowing hot air when it's 30 degrees Celsius.
Might have switched the fan and the call for heat/cooling (temperature) signal wires. See if you can have someone ring out the wires and make sure they are correct.
PS dont feel dumb for having problems like this, I know about this because I did it once or twice. Now I tag the wires and make a diagram which stays on the wall behind the thermostat. That way its there for future reference if you have to get back in there, or if it gets worked on by someone else.
you have connected your ac wires and heating wires together,look at your thermostat wiring diagram,you should have marked the wires.
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