Common Reasons Why Your Air Conditioner is Not Turning On Resetting your thermostat is often all that's necessary to get it working again. A tripped circuit breaker is another common reason why your AC won't turn on.
Power issues: A tripped circuit breaker or blown fuse in your home's electrical system will prevent your AC from starting. Thermostat problems: Make sure you have your thermostat set to “cool” and the temperature is set below the current temperature in the room.
If the wires are frayed, not connected, or dirty, your air conditioner will not be able to turn on. Another common problem is a faulty thermostat. If the thermostat malfunctions, it will not send the signal to the air conditioner to turn on.
The main reasons your AC unit outside is not turning on could be something that has tripped the circuit breaker, something is blocking the fan's airflow, or the condensing unit is damaged. Other potential issues could be the thermostat isn't set correctly or the compressor could be malfunctioning.
If your thermostat is set to cool but your AC isn't turning on, there could be several potential causes ranging from a simple tripped breaker to more complex refrigerant or compressor issues. Start with the basics, like checking the thermostat settings and power supply, and work through more detailed troubleshooting.
Blowing the fuse cuts the power to the unit to prevent electrical damage. If your AC has shut down and won't start again, especially if you've noticed odd electrical behavior immediately before the shutdown, chances are the fuse has done its job and will need to be replaced.
Look for a RESET Button.
Some systems have a RESET switch on the outside unit. You can push this and see if it helps. If your unit does not, you can turn off the system at the thermostat, wait 5 minutes, and try again.
A sure sign of a bad AC capacitor is a humming sound from within the access panel. Any humming noises indicate a problem with the air conditioning system or the components of the AC unit. Try turning the power on and off again to see if it was a one-time issue with the motor or a recurring problem.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
Over time, the fan motor on the outside AC unit can wear out, causing the outdoor unit to stop working even when the inside AC unit is on. The fan motor can last 10 to 20 years with proper maintenance, like annual inspections and regular AC unit cleanings, but it will wear down faster without regular maintenance.
Check these issues when the unit won't kick on: Check the thermostat and adjust the settings if it isn't set to Cool and an appropriate temperature setting to call for cooling. Examine the house circuit breakers for the AC unit and reset any tripped breakers. Check the air filter and replace the filter if it's dirty.
The easy explanation for your AC not turning on is a thermostat issue. Double check your thermostat is on, set to “cool,” and that the temperature is set to a few degrees colder than the normal ambient temperature of your home. You may also need to replace the batteries.
To fix an AC not blowing cool air, ensure the thermostat is set to "cool" mode and the temperature is set lower than the current room temperature. Inspect the air filter as a dirty filter can restrict airflow. Ensure the condenser coils are clean and free of debris. Make sure vents are open and unobstructed.
It's a small, red button usually located on or around the unit. The button should have a clear 'reset' label. Once you find the button, press it for around three seconds and observe the AC. Check whether the AC kicks on immediately and if it doesn't, press the button again for another three seconds.
#1 Most Common Air Conditioning Repair – Bad Capacitor
The fan of course makes a whirring noise, the compressor is like a deep buzz like a refrigerator running. Holding your hand above the fan should feel warmer than the outside air.
How to test a bad capacitor? Connect the multimeter probes to the capacitor and set it to capacitance mode. Then, take the value and compare it to the expected value of the capacitor. If it is within 10-20% it is good, if not, it is bad.
Look for a Tripped Breaker
If your AC won't turn on, you can check two places for a circuit breaker or electrical panel. Older homes have a main electrical panel on the outside of the home or a circuit panel on newer homes. Check the electrical panel to see if the breaker is tripped. Reset it if it is.
For AC capacitor replacement, anticipate spending between $150 and $400, depending on the capacitor's type and accessibility.
Check the power source and make sure it is connected and turned on. Verify that the circuit breaker for the AC unit is not tripped. Make sure the thermostat is set to 'COOL' mode. Check the fan setting on the thermostat and ensure it is set to 'AUTO' rather than 'ON'.
AC Fuse, Circuit Breaker, or Relay Replacement Cost
Expect to pay between $15 and $300 to have AC fuse and circuit breaker issues addressed or relays in your AC unit replaced. These projects do not usually take more than a couple of hours.
Air conditioners can stop working if there is a blown fuse. Replacing that fuse can fix the problem, though it's important to have a certified car AC service technician check your electrical system.
Where is the AC Fuse Located? The AC fuse on most HVAC systems is typically on the unit's control board. You'll normally find the board behind an access panel on the unit's lower compartment. While you sometimes have to unscrew areas to access the control board, others have clips.