Why Isn’t My Outside AC Unit Not Turning On? Simple Tips To Fix This Issue!

Outside AC Unit Not Turning On

Homeowners generally depend on their AC unit to stay cool during the hot summer months, however, when your outside AC unit is not turning on, you might think “why isn’t my outside AC unit turning on?”. So, it is really important to know what the problem is and find a solution as soon as possible. 

According to the report of the U.S. Energy Information Administration, 87 percent of US homes have air conditioning. Because a right-sized home AC unit can keep you and your family cool in extremely hot weather. 

And as there are so many different elements in air conditioning systems, keeping track of the current condition of all of them can sometimes get really difficult. That is why dealing with an outside AC unit not turning on can be extremely frustrating.

In this article, we have discussed why your outside AC unit isn’t turning on and what you should try to get it working again. Also, here we have covered the system specifications of your AC unit and how you can reset an AC unit. 

So, let’s get started.

Understand The System Specifications Of Your AC Unit 

Air conditioners have several specifications and all of these are equally important. Following are the specifications which you should know what they actually mean.

  • Capacity: Cooling capacity is measured as the quantity of heat energy that an air conditioner can remove within a given period of time. Cooling happens faster when the cooling capacity is greater.
  • Running current: Electrical Current During Operation Running current is the quantity of electrical current running through an AC during operation. It is a significant term to technicians when used to determine the quantity of refrigerant required for an AC.
  • CSPF: Efficiency- CSPF is an acronym for cooling seasonal performance factors. It is a number that denotes the energy efficiency of an AC. The higher the CSPF, the energy efficiency of an AC becomes greater.
  • Rate Of Airflow: Air Volume Over Time the rate of airflow is the quantity of air volume distributed by an AC within a specific duration of time. The higher the rate of airflow, the more the wind but, noisier the AC.
  • Sound Pressure Level: Sound pressure level refers to the noise level generated by an air conditioner. Usually, for both the outdoor and indoor units, a sound pressure level is available.
  • Refrigerant: Refrigerant denotes the type of refrigerant used for an AC. Here are examples of some commonly used refrigerants, namely, R22, R32, R134a, and R410a.
  • Power Supply: Electrical Requirement is a power supply or power source is the required electrical characteristic to function for an AC. The power supply is segregated into three forms; phase, voltage, and frequency.
  • Power consumption: Power consumption is the usage of power by an air conditioner, which is expressed in Watt or Kilowatt. When we multiply power consumption by the hours of working, it gives us kWh. We then multiply this kWh by the electricity rate to determine the cost of electricity.
  • Energy rating (1 to 5-star): The energy rating of an air conditioner is its energy efficiency rated by an authority. The energy rating is not the same for every country. The lowest is 1-star while the highest is a 5-star rating.

Why Isn’t My Outside AC Unit Not Turning On: Top 11 Highlighted Problems

It becomes very important to find the root cause of any problem in order to find the solution. That’s why we have shared below some of the most frequently occurring problems due to which the outside AC unit does not get turned on.

1. No Power Due To A Blown Fuse 

First of all, check whether the fuse of the disconnect switch is in the right condition or not. Remove the fuse and measure the resistance with the help of a multimeter. If the multimeter reading is zero, then the fuse is good.

And if it shows high reading then the fuse is bad and this must be because of overcurrent, lightning, and something like that. Now, replace the damaged fuse with the new one which matches the maximum current of the outdoor unit.

2. Problem With Contacts On The Contactor 

Check for the burn marks on the magnetic contactor. And, if found that means, the contactor has become damaged. Make sure that the power supply is cut off before replacing that bad contactor with the healthy one.

3. Bad Thermostat Connection From The Indoor Unit To The Outdoor Unit 

Ensure that the connection wires are not directly exposed to the environment.

Check for proper insulation of the wires so that both indoor and outdoor units are having a proper connection with one another.

4. Failure Of The Capacitor 

A capacitor possesses the energy that is needed to power up the outside AC unit. In case the capacitor gets damaged, a buzzing sound will come from the outdoor unit.

An AC unit has either one of the two capacitors, whether a run capacitor or a start capacitor. No matter which capacitor, it fails due to aging and wears over time. Overwork and enormous heat contribute to speeding up this process of failure.

5. Problem With The Condensate Drain Line 

In an AC condensate drain line, water gets eliminated while the conversion of refrigerant from liquid to gas is taking place. 

This drain line can get choked due to high humidity. So, once it’s choked, the drain line will fail a safety switch due to which the air conditioner is turned off.

6. Clogging Of The Air Filter 

Check the air filter. If the air filter gets clogged with dust and other foreign particles, it blocks the flow of air into the system. This can lead to overheating and eventually, the equipment is turned off.

7. Thermostat Not Working Properly

The first thing to do is to check the thermostat is on and battery-powered. In case, if it’s off, turn on the thermostat. And if it is still not getting on, replace the batteries with the ones which are fresh and ready to use.

8. Flipping Of The Emergency Switch 

An AC unit has such power sources that automatically get turned off when AC not works. So, in this case, go to the place where the outdoor unit is positioned. 

Nearby the outdoor unit, locate that place where an emergency or shut-off switch is present. Ensure the switch is in the “on” position and plugged in. You may also push the reset button if present on the outdoor unit.

9. Low Amount Of Refrigerant 

A refrigerant is a chemical substance that cools warm air from the outside surroundings. The refrigerant circulates through a closed loop, which means that leakage is most likely to occur within the system if the unit is low on refrigerant.

Due to this, an outside AC unit stops working and may not even turn on again. Signs of leakage are:- ice gets buildup on the outside of the unit, only warm air releases from the vents, and a hissing noise near the air conditioner.

10. Exposed Live Wires Without Proper Insulation

There are several wires that connect one part to the next part of an air conditioning system. Some of the wires are exposed above ground level, while others are hidden behind the walls.

When these exposed live wires get eroded or damaged due to any reason, an air conditioner becomes impaired and not even get turned on. Therefore, to avoid this situation, exposed live wires should have proper insulation.

11. Power supply Or Power Source Problem 

Now, check for the power supply. Measure the voltage at the outdoor unit is around 230 or not. If the voltage is found normal then ok, otherwise, go to the indoor circuit breaker box, and ensure the breaker is in the off position. Also, check if it keeps tripping or not.

If the outer unit is drawing a much lower current than the indoor unit, then call an electrician and get that defective breaker replaced with the new one.

How Can I Reset My AC System Settings?

The most common reason to reset an AC unit is when it blows only warm air, even when the thermostat is set in cooling mode. While an air conditioner can be reset easily, you need to just follow these 4 simple ways.

1. Using the reset button 

An AC unit may not start if the compressor does not activate the electrical system. Such faults are common and may be solved by using the reset button.

Before resetting, ensure a sufficient power supply. Once you have verified there is power, you can restart your AC unit.

2. Reset the isolator switch  

An air conditioner is well equipped with an isolator switch that houses between the equipment and the main supply of electricity. Your AC gets successfully restarted just by switching it off and on.

By locating the isolator switch present on the outdoor unit, you will be able to reset the system. Once you got the isolator, turn it off and just wait for half an hour. 

After that, you can turn the lever of the switch “on”. Your AC will restart without reporting any problems.

3. Reset the circuit breaker  

If you are not able to reset your AC unit by using the reset button or isolation switch, try to reset the circuit breaker.

Inside the breaker box, locate the circuit breaker labeled as “AC” and turn it off and after some time, turn on that circuit breaker. Now, restart your AC and verify it is working.

4. Reset the thermostat 

The next possible action you can take is to reset the thermostat. The thermostat sends a signal to the air conditioner to cool the air depending on readings of the temperature. If it is defective, the system will not at all work.

Resetting the thermostat is an easy process. You can restart the system by pushing the reset button for five seconds only. Usually, the reset button will be under cover of the thermostat.

What Other Ways Can I Use If My AC Unit Is Not Turning On?

If an air conditioner is not getting turned on, the most probable reason is that there may be a malfunction. For any additional help, you may call your local HVAC technician. 

Malfunctions range from easy-to-fix issues like a choked filter to more technical problems such as leakage of refrigerant.

By detecting the malfunction on time, you will be restricting microbial growth by taking some action. Also, you can protect the equipment from algae. 

In case the air conditioning system is already prone to microbial growth on critical components. Then you need to consult a certified technician.

Even if your AC simply won’t turn on, you will be the one to decide whether to repair or replace the unit. In order to fix the repair, contact the HVAC technician.

Generally, units that are over 12 years old should be replaced with units that are more efficient. However, repair costs of units should be evaluated carefully prior to making a decision. 

If the cost of repairing will be more than 50 percent of the overall value of your unit, then replacing the unit is a better option. 

Wrap Up On Why Isn’t My Outside AC Unit Not Turning On 

There are several problems that can cause an air conditioner to not turn on. Usually, when the circuit breaker gets tripped by something, the outside AC unit does not turn on.

When this happens, after getting the circuit breaker panel, you can reset it easily. In case the AC unit still does not work, the next action is to check the thermostat.

A thermostat that is non-responsive will fail to go hand in hand with the rest of the air conditioning system. In some cases, something simple like power can resolve the problem. And if not, there may be a major problem related to the thermostat and wiring.

We hope that our useful information has helped you a lot to know about the problems that prevent the outside AC unit to turn on. If you have any queries regarding the air conditioning system, do not hesitate to clear your doubts.

FAQ: Why Isn’t My Outside AC Unit Not Turning On? 

Nowadays, people come across a lot of questions regarding air conditioning systems that are yet to be answered. That’s why I have tried to answer a handful of such frequently asked questions.

Q1. What controls the outside AC unit?

Ans: The thermostat mainly controls the outside AC unit which is present behind the control panel. The unit will control the current temperature by heating or cooling the air. Once it comes to the desired temperature, it will continue to examine the air and turn the system on, if needed.

Q2. Is there a reset button on the outside AC unit?

Ans: Not all, but some AC systems have a reset switch, typically located on the outdoor unit. A small, red button on the outside AC unit symbolizes the reset switch. If you face any problem searching for it on the outdoor unit, you may refer to the air conditioning unit owner’s manual.

Q3. How do I know if my AC unit is broken?

Ans: In case your AC unit is broken. You will find warning signs such as warm air, the inadequate flow of air, frequent cooling cycles, high humidity, leakage of water, unpleasant smell, and unusual noise.

Hey, I am Kirtish Vyas a YouTuber and believer in making life peaceful, a couple of years back I started soundproofing my house, bedroom, studio, and Car to reduce the unwanted noise, and the same experience I am sharing on SoundProofidea. Read More