Power down your AC: Turn off your AC unit and unplug it from the power source. This will ensure that you stay safe while working on the unit. Locate the reset button: Most air conditioning units have a reset button located near the outside unit. It is usually a small button located inside a small hole.
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.
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.
Your AC unit may in fact have its own reset feature already. This feature will likely perform this entire process for you when selected.
After finding the circuit breaker for your AC unit, flip it to the off position. Leave it off for around 30 minutes, then flip it back to the on position. If you have fuses, you can only reset the AC by taking the fuse out.
One AC, Two Breakers
Most central air-conditioner systems incorporate two circuit breakers. One protects interior components such as the air handler/blower fan inside the house. Another circuit breaker protects the outdoor condenser unit, including the compressor.
If you think your air conditioner has blown a fuse, the first sign you'll notice is that the outside AC unit is inoperable. The best way to check for a blown fuse is by using a voltmeter. Be warned — you are working with live electricity and should use extreme caution when troubleshooting your system.
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. Using too many appliances at once can trip the circuit breaker.
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.
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.
Turn the system off through the thermostat or breaker to do a reset. Wait for a minute before turning it on again. Check if your cooling unit is back to normal. If it isn't, hire an HVAC technician to help you with further troubleshooting.
However, not all units have one, and it's essential to consult your user manual or an HVAC professional if you're unsure. Remember, while the reset button can be a quick fix, persistent problems should always be addressed by a qualified technician to prevent further damage and ensure your system runs efficiently.
Typically, you can find the switch for the indoor unit near your system's furnace or air handler. You can find the switch for the outdoor unit next to the outdoor unit, usually in a metal box on the exterior of your home.
Some air conditioning systems have a reset switch, which is a small, red button. Typically, the button will be on the outdoor unit. If you have a problem locating it on the outdoor unit, you may find relevant details on the equipment's manufacturer's manual. Press the red button for three seconds and release.
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.
Check Your Circuit Breaker
Locate your main circuit breaker and switch it back to the "On" position. Wait 30 seconds and turn on your air conditioner again. If it still doesn't work, you'll need to call a professional for help.
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.
Wear and Tear on the Fuse
The lifespan of a fuse can be up to 20 years. AC fuses are usually what is known as 'slo-blow' or 'time delay' fuses. This means that they are at work every time you turn the machine on and off and eventually, will simply wear out due to the strain of the operation.
If You Don't Have a Reset Button on Your Outdoor Unit
Unplug the unit from the power supply board and disconnect the system. This ensures that the AC unit is receiving no power whatsoever. Wait 30 minutes, then plug the unit back in.
Circuit breakers can be found in homes, businesses, and industrial facilities. They are typically located in the main electrical panel, which is typically located in the basement or garage.