Why is my cooling not working?

There are several reasons this may be happening. Try these troubleshooting tips:
 

Is your furnace or air handler (blower) turned on? Check the circuit breaker for your equipment. Also, make sure the furnace or air handler door is closed.

Is your thermostat set to Cool mode? The set point (the smaller number at the top of the thermostat display), should be set to a temperature lower than the display temp (the larger number in the center of the display).

Is the “Cool On” message solid (not blinking) on the thermostat display? Verify your thermostat’s wiring.

Check that the wires are connected securely to the terminals. Remember, the color of the wires only relates to the terminals they are connecting.

Reference: The Y terminal on your thermostat controls the primary (1st stage) cooling. (Or the Y and O/B terminal if you have a heat pump system) In addition, the G terminal activates the fan to circulate the cooler air in your home.

Determine if your jumper / R wire is connected correctly.

Thermostats receive power on the R and Rc terminals. Here are the variables to examine:

• If you have a wire in the R terminal and no wire in the RC terminal, use the jumper selector switch, the jumper plug, or a small jumper wire to connect the R and Rc terminals.
• If you have a wire in the RC terminal but no wire in the R terminal, move the wire from RC to the R terminal and use the jumper selector switch, the jumper plug, or a small jumper wire to connect the R and RC terminals.
• If you have a wire in the R terminal and another wire (not a jumper) in the RC terminal, you will not need to connect the R and RC terminals.
• If you have any questions or see wiring that seems incorrect, check with a certified HVAC

Are your Outdoor Compressor and Indoor HVAC system/vents working correctly?

When the thermostat requests cooling, the outdoor compressor should be running.

• If your compressor is running, but the air is not blowing through the indoor vents, you may have an issue with the indoor HVAC unit’s fan.
• If your Indoor HVAC unit fan is running and your Outdoor Compressor is not, it’s likely an issue with the Compressor itself. In both cases, check with a certified HVAC Technician.

Advanced steps:

Using a multimeter, measure the AC voltage between your Rc wire (or R wire if no RC wire is present) wire and your Y wire. Your thermostat operates between 20-30VAC, any reading outside this range should be addressed by a Professional Contractor.