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.
Several thermostat issues can cause your air conditioner not to turn on. One of the most common problems is disconnected or loose wires. 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.
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 thermostat clicks but the AC or furnace doesn't turn on, most often it's because the filter is clogged. A blocked filter will restrict airflow. The particles it's designed to trap eventually clog the filter media, and the system will be unable to generate heat or cool air.
Solution: Begin troubleshooting power issues by checking the thermostat's power source. If it's battery-operated, ensure the batteries are functioning and correctly installed. Inspect the circuit breaker for hardwired thermostats to confirm it hasn't tripped. Reset the breaker if necessary.
Faulty or Malfunctioning Thermostat
If your thermostat clicks repeatedly and your AC doesn't turn on, it usually indicates that the problem is related to the thermostat itself and could be caused by either an issue with the thermostat relay or the system's wiring.
There is usually a small reset button somewhere on the thermostat. Finding this button may require that the thermostat panel be removed and pressing this button may require something like a paperclip to push. Hold the reset button down for 5 seconds and the thermostat should reset.
Signs of a Faulty Thermostat
AC Refuses to Start or Stops Suddenly: A thermostat that's not working correctly might fail to initiate the cooling cycle or might randomly shut off the AC. This erratic behavior can be due to electrical issues or miscommunication with the AC unit.
Check your home's circuit breaker panel.
When that happens, your AC can't turn on. If a circuit breaker has tripped, it will switch from the "on" position to the "off" position. Reset any tripped breakers by flipping them back to the "on" position.
First, make sure the register damper is open. Then remove the register cover and check for visible dust and debris clogging the duct. It's also a good idea to check your AC filter and see if it's clogged with dust. If so, get a new filter and replace it.
If your home's central air isn't working at all, check the main electrical panel in your house. It could just be a tripped breaker or blown fuse. If that's the issue, just reset the breaker or replace the blown fuse. Your thermostat setting could be another reason why your central air isn't working.
Try checking the circuit breaker box or replacing the batteries. Bad wiring: The thermostat may be unresponsive if the wiring has gone bad. Remove the cover and check inside for loose, detached, or corroded wires. If you spot any problems, contact an HVAC technician for assistance.
Locate the sensor, which is a small, round component usually positioned near the bottom of the thermostat. It may be labeled as “sensor” or “thermistor.” Using a soft brush or a can of compressed air, carefully clean the sensor to remove any dust or debris that may have accumulated on its surface.
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.
Replace Dead Batteries
While some thermostats are hardwired, many use batteries or have batteries as a backup power source. Dead batteries are one of the most common reasons a thermostat may fail to turn on the air conditioning system, leading to a loss of connection and inability to activate the HVAC system.
Any time you are having an issue with heating and cooling units, such as after a sudden power failure or after your children have had 'control' of the system while you've been away, resetting the thermostat should be the first thing you try when attempting to rectify HVAC system issues.
Yes, a dying battery in your thermostat can have an impact on your HVAC system. If your thermostat's battery is low, it can cause your HVAC unit to function erratically or potentially not at all. Your thermostat plays a huge role in how your HVAC unit functions as it regulates the temperature of your system.
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. This is also common when there are power surges after a big storm.
Some possible solutions include resetting the thermostat to factory settings, checking the circuit breaker, replacing the air filter, checking the outdoor unit, checking the indoor unit, replacing the thermostat's batteries, and checking the connections and wiring for any damage.
Make sure the outside unit is turned on (there's probably a switch near the unit). If the outside unit has a separate circuit breaker, check your circuit box and make sure it hasn't been tripped. A more serious issue if the outside air conditioning unit's not working is a broken compressor, capacitor or fan.
Locating the Reset Button
Remove the thermostat cover by either snapping it off or unscrewing it, depending on the model. Most modern thermostats will have a clearly marked reset button inside the panel. It's usually small and recessed, so you might need a pointed object like a paperclip to press it.
Try replacing the batteries, then check for a blown fuse or tripped breaker in the electrical panel. If the thermostat is still unresponsive, make sure the breaker is shut off and remove the cover.