Informational Guide

How To Fix An AC That Won't Turn On

Air conditioners are renowned for issues such as not switching on. Learn our to diagnose and fix an AC that won’t turn on.

by Josh M

Did you know that 75% of homes in the US have air conditioners? An AC is important, especially in certain parts of the country. Air conditioners make your house comfortable to live in, and you need to make sure that it’s kept in good condition, especially when you want to use it during the scorching summer months.

Are you having problems with your air conditioner not turning on? Then keep reading this guide to see what would cause an AC unit to not turn on and how to fix it.

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Thermostat Malfunction

Your thermostat may be malfunctioning which leads to your AC not turning on. If you notice that the thermostat is still acting up after the batteries are replaced, then that’s one of the telltale signs it’s reached a dead end.

Additionally, if you notice cooler and warmer rooms or uneven cooling, that could also signal a disrupted thermostat. Some other causes might be dirt, dust, or other grime that has gotten into the sensitive parts. Another possibility might be loose screws/wires or simply the advanced age of the model.

If you change into a fresh set of batteries, clean the unit, and check for any faulty parts, yet your thermostat is still not functioning well and giving inaccurate temperature readings, contact a professional to check it out. Leaving this issue unresolved could lead to other problems down the road.

Related ArticleHow To Reset AC Thermostat

Low On Refrigerant

Leaks in the line or the compressor can cause a low refrigerant content in your AC. It’s a tricky problem; most of the time, refrigerant evaporates, leaving no trace of any issue. Refrigerant is crucial for the air conditioner. Through this process, heat is removed, and the house is cooled. If the refrigerant runs too low, coils can frost over and damage the compressor.

Trained professionals can tackle this issue, close up the leak, recharge the refrigerant, and get your air conditioner back to normal.

Blown Fuse

A blown fuse is concerning as it not only harms your AC unit but can also subject people to injury and damaged property. A fuse is blown due to an electrical overload most of the time.

For example, when the weather outside is reaching astronomically high temperatures, the AC has to work overtime. A clogged motor or filters contribute to a more likely possibility of having a fuse blown. Dirty coils or circuit problems are also likely perpetrators.

Listen for weird noises, such as buzzing, humming, or clicking. Another option is using a voltmeter to look for blown fuses. You can investigate further, but make sure you have a basic knowledge of how ACs work.

Clogged Air Filters

Dirty filters limit the airflow, reducing the ability of your unit to function properly so your air conditioner won’t start. When the flow of air is hindered, air passes the filter and deposits dirt into the evaporator coil, which affects the coil’s heat-absorption ability.

Filters are located along the return duct’s length. Some filters are reusable; others need to be replaced. Clean the AC filtering system every month or two, but they may need more frequent attention when used constantly or if you have furry pets.

Dirty Air Filter of Air Conditioner

Tripped Circuit Breaker

If your AC is tripping your circuit breaker, there may be several underlying issues as to why it keeps doing that. Some examples include that the AC is not getting enough electricity or overheating.

You can turn your air conditioner off at the thermostat, then head to the breaker; turn it off, then on, and adjust your thermostat. Make sure the temperature is five degrees lower than room temperature, and your AC will turn back on.

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AC Capacitor Died

High/hot temperatures are the main reason why your AC capacitor isn’t working any longer. If exposed to heat for too long, a capacitor loses its ability to maintain an electrical charge, which leads to motor failure.

Listen to any clicking sounds coming from the AC when starting. If a capacitor dies, it needs to be replaced, and it’s best to leave that to the professionals.

Unplugged Condenser

Sometimes, everyday tasks cause your condenser to unplug, which interferes with the AC process, especially if your outside AC unit is not turning on. So if you or something else accidentally or purposely unplugged it, it’s an easy fix without much hassle. Just make sure the condenser is plugged in correctly.

Clogged AC Drain Line

ACs absorb the heat and humidity from your home, making your living space pleasant. This humidity condenses through the coils and goes into the drip pan, which leads to the drain line.

Since it’s a closed, wet space, mold and other sludgy goop can build up, clogging the line and making it impossible to drain the extra moisture. If not addressed, the pan will continue to fill and cause damage.

Water and vinegar can help unclog the drain line, but remember to turn off your AC beforehand to avoid an electrical shock. Check if any visible debris can be removed before pouring the solution inside and replacing the cap.

Dirty Evaporator Coils

Over your AC’s years of service, dirt and dust will accumulate, despite having a clean filter to help manage the amount. This dirt will reduce airflow and limit a coil’s ability to absorb heat.

Check your evaporator coil every year and clean it as needed. Outdoor condenser coils can become very dirty, so keep any foliage trimmed and clean the area around the AC. If necessary, you can spray water to clear any leaves collected within the unit.

AC Fan Dormancy Issue

A fan pumps air through the unit, and the AC will not work unless air is flowing. Because of its important job, the fan can wear down easily. Some noticeable issues are if the fan works despite the AC being off or the fan rotates slowly or not at all.

Listen and look for any symptoms. Check for a circuit breaker issue, air filter issues, and the unit outside. When in doubt, contact a technician.

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AC Motor Failure

Elements in the motor fail over time and use. Electrical insulation weakens if exposed to voltage imbalance and temperature, to name a couple. Dirt, moisture, fumes, and misapplication of lubricant are just a few other reasons why your air conditioner won’t turn on.

If a key part, such as a bearing fails, the motor should be replaced. Depending on the type and replacement cost, larger motors can sometimes be refurbished. An AC motor can last between 30,000 and 40,000 hours, but the environment also plays a role.

Faulty Power Cord

Plugging and unplugging power cords will inevitably lead to them wearing down and will need to be replaced, or safety hazards become more likely.

Fixing a faulty power cord takes a few hands-on steps. You should unplug your AC and remove the front panel, locating where the cord is attached within. You’ll see multiple wires, and after determining which one is not working, you can replace it by removing it from its corresponding connector. Finally, check to see if your air conditioner is functioning properly.

False Temperature Readings

If your thermostat is showing false temperature readings, there are a few causes to why your AC won’t kick on in the house. First, the thermostat might be outdated without having the features of newer models.

Another few possibilities are that the sensors could be malfunctioning or the model itself isn’t level on the wall; in other words, it wasn’t installed correctly and is giving inaccurate readings.

A service professional is the wisest move if your thermostat gives false temperature readings. If this persists, you might see incorrect electricity bills and make more repair calls since the device can’t communicate with the AC unit.

Honeywell thermostat wall

AC Switch Shut-Off

If your AC is shutting off randomly at moments you don’t want it to, then it may be experiencing one or many of the above issues we already addressed in this article, like a faulty thermostat or lack of airflow.

Another suggestion would be that your AC is short cycling, meaning that when it turns off, it turns back on rather quickly. When this cycle repeats, your air conditioning won’t turn on, which may lead to damage.

You can contact a professional to analyze whether or not your AC is the right size for your home or if your thermostat was placed in the appropriate location, especially if it was a newer installation.

Related: How To Troubleshoot The HVAC Low Pressure Switch

Air Conditioner Beeps But Doesn’t Turn On

If your air conditioner beeps but doesn’t turn on, that noise might suggest that your AC could have various problems. If it happens multiple times, then your unit is giving a specific warning of some kind that needs to be addressed.

A few possibilities include that the power is out (aka the circuit breaker tripped), there may be a faulty sensor in the AC unit, or condensation accumulating.

The filters might need to be changed, or the batteries in the thermostat are low. Regardless, if you are hearing beeps, it should not be taken lightly. You can investigate or call a professional for a second opinion.

How To Manually Turn On Your Central AC Unit

If your remote isn’t working, that doesn’t necessarily mean there’s anything wrong with your AC unit, and you may have to replace the batteries of the wireless control. How to manually turn on an AC unit is simple, and you can usually find the switch-on button underneath the front panel.

People Also Ask (FAQ)

How can I make my AC unit last longer?

The best way to ensure that your air conditioner works for many years to come is to not use it constantly and opt for other cooling options, such as fans. Let it have a vacation during the cooler months! Be sure to clean it regularly, have preventive maintenance checks, and change the filters.

Can I reset my AC if it doesn’t turn on?

Yes, you can reset your AC by turning off your air conditioner via the thermostat and shut off the unit entirely by locating the breaker box. After a minute, switch it back on. Wait for at least a half-hour before adjusting the thermostat again so the AC can reset.

Related ArticleReset Button On AC Unit Outside

Are carrier AC units prone to not turning on?

Carrier AC units are top quality, and their products are efficient and affordable. They rank high in energy efficiency and are prone to functioning well with guaranteed values as long as they are properly maintained.

Conclusion

Hopefully, this article has provided you with the right knowledge to troubleshoot if your AC won’t turn on and give you insight into how to fix them. Remember that many of these issues can be fixed at home if you have a background with your AC unit; however, professionals in your area can take a look whenever you’re uneasy approaching a problem alone.

Last Updated on May 25, 2022

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.

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