AC Troubleshooting - No Cold Air in the Summer

hand in glove brushing air conditioner filter

It's one of those universal laws of nature that on the hottest day of the summer, your AC is going to stop working.

No cold air in the summer requires AC troubleshooting, something that's only going to work if you have a working idea of what causes air conditioner problems and what you can do to address them.

There are several air conditioner problems that homeowners can address on their own with some basic DIY skills, so don't stress out too much if you have no cold air in the summer.

AC troubleshooting can help you solve several problems that will affect airflow and may help you get back to cooling airflow again without too much work and trouble.

AC Troubleshooting You Can Do

The air conditioner is a pretty complicated machine, with various parts and functions that are not easy to understand, even upon close inspection. However, there is plenty you can do on your own to troubleshoot and treat common AC problems.

Check the Filter

One of the easiest problems for homeowners to address is a dirty filter. A dirty filter can cause the airflow from vents to be reduced, which can hamper the cool air going into your home.

A clogged filter can even cause ice on the refrigerant lines, which will literally freeze up the system and keep the cooling airflow from flowing. You may even see water leaking and high energy bills when an AC filter is dirty.

Change out the filter so that your air conditioner is getting proper airflow. The filter should be changed about once a month.

Make sure you have the right size filter. They come in all different sizes, so measure your existing filter to get the right one.

Check the Power

If the AC isn't blowing at all, go take a look at your breaker box. One of the breakers may have tripped, which means it has flipped itself off.

This is the easiest fix of all. Simply flip the switch back to the “on” position and see if the air starts to flow again.

One or two breaker trips over time are no cause for concern. But if the breaker begins tripping regularly, this is an indication of a bigger electrical problem that may indicate faulty wiring and you should have this checked out by an electrician.

Check the Condenser

You most likely have what's known as a split AC system, which means there is an indoor and an outdoor component. The outdoor unit is the condenser and it could be dirty or clogged, which will affect the amount of airflow you feel inside.

Use a hose to clean off the condenser using a gentle spray of water. Grass clippings, dirt, and other debris from the yard can build up on this unit over time and that can greatly impact how effectively it functions.

Plain water is enough to clean off this part of the system, but turn off the AC first before you start spraying water all over it, and give the unit about 30 minutes to dry before you turn it back on again.

If any plants or grass are growing near the unit, clear this away. Plants that are near the unit can also impede airflow to the unit and reduce the cooling effect you feel inside.

Perform this maintenance regularly and you will experience fewer AC problems over time and may even extend the life of your air conditioner.

hands opening air conditioner compressor

Check the Drainage

AC units are blowing cold air into a hot space, so condensation is only natural and expected. The condensation created by the AC has its own drain pipe and drip pan, which catches excess water.

When this pipe or the drain itself becomes clogged, this can cause water to build up. If there is water where it shouldn't be inside your AC unit, this will trigger an automatic shut-off and can even cause bigger problems for the unit.

Test the drain pipe and drain by intentionally pouring a little water down the line and into the drain. If the water flows smoothly, you can rest assured that the drain is working properly and go troubleshoot something else.

If the water doesn't flow, try unclogging the pipe with a straightened coat hanger and see if this pushes the blockage through the line. Lift the grate cover on the drain and clean out any hair or debris that may be impacting the water flow.

If this still does not fix the problem, try to clean out the drain itself with a snake and pour water down the drain again to test it.

If you have a clog in the drain that you can’t clear, call a plumber. They have special tools and equipment that can be used to address clogs in a safe way and get rid of the debris that is clogging the line.

Inspect the Thermostat

There are a few things that can go wrong with your thermostat that can make the AC stop working properly, so you definitely want to troubleshoot this if you’re having airflow issues.

Check the thermostat settings first to see if the temperature is set to a temp that's lower than the temperature inside your home. Also check the fan settings to make sure everything is set the right way so that cool air will blow.

Next, see if the thermostat batteries are bad. Some thermostats have batteries, so if yours does, this could be the whole source of the problem.

If you have a digital thermostat, get into the settings and make sure all of these are correct. You may also want to run a troubleshooting mode on the thermostat, if present, to see if there are any other problems happening here that aren’t immediately evident.

Flickering AC Lights

Do the lights in your home flicker when the air first kicks on and starts to blow? This is a strong indicator that there is a problem with your electrical wiring, not with your air conditioner.

Flickering lights that occur when the AC is blowing suggest that the air conditioner is using too much power, more than it should be using, in order to function. It’s pulling power from other areas of the home in order to supply enough resources to the air conditioning.

This means you need the services of an electrician to check for wiring problems that are creating this issue because the AC should not be working so hard it’s pulling electricity away from other parts of your home.

Don't hesitate to have this problem inspected, as problems in your electrical wiring can lead to further failures of home appliances, and it can even create a serious fire hazard if the wires are frayed or damaged in any way.

Other AC Problems

If this basic AC troubleshooting goes nowhere, you may have another air conditioner problem, such as low refrigerant levels, faulty wiring, or worn-out equipment.

These issues require professional service, so you should now consult with an HVAC professional to further diagnose the problem once you’ve exhausted all your DIY troubleshooting options.

No Cold Air in the Summer

You clearly can't last long without a functioning air conditioner in the hot summer months. Go through your AC troubleshooting, and hopefully, you will find that the air has been compromised because of a simple problem with a simple fix.

In other cases, you may need further services from a professional, but the sooner you get the problem fixed, the better. The longer problems are left untreated, the bigger those problems end up becoming in the future.

A clean and functioning air conditioning unit will cost you less money in utility bills than one that is working overtime to compensate for electrical problems, dirty air filters, and other problems that lead to a weakened or warm airflow.

AC Troubleshooting FAQs

Why is AC running but not cooling?

It can be very confusing and frustrating if the AC unit is blowing air, but the air is not cool, because obviously, the system is working in some capacity. This particular problem can actually be caused by several problems, not the least of which is ice on the condenser.

Ice can build up when the AC is running too much. While this can be caused in a heat wave in times of very high outside temperatures, it is usually an indication that something is wrong with the system that is compromising its functionality.

The air conditioner shouldn’t be running so much and so hard that it’s freezing up inside. When the coils get ice on them, the AC can still blow air, but the air won’t be cold because the cooling coils have been compromised.

Replace air filters, check the air conditioning drain line, and make sure the thermostat has fresh batteries and that it's set the right way to blow cool air. These simple fixes may be enough to restore the cool air.

What are common problems with air conditioners?

Many things can go wrong with air conditioners, including the usual issues of parts inside the unit simply wearing out over time. However, you may end up facing a much simpler fix, such as a dirty outside AC unit that is clogged with debris.

Dirty air filters, clogged condensation lines, and improper thermostat settings may all be causing the air to not flow properly as well. Do some basic AC troubleshooting on your own before you call the professionals, because you may find that the AC problems you're having can be fixed simply.

What is the average life expectancy of an AC?

There are many different types of air conditioners out there and you can even come up with some interesting DIY options when you need cool air, so there is no specific time limit for how long any given AC unit will continue to work.

But generally speaking, a typical home air conditioner should last you about 15 to 20 years before it needs to be completely replaced. Regular maintenance can extend the life of the system by a few years, but even with great maintenance, all things wear out and break down over time.

Is it bad for an AC unit to run constantly?

If you noticed that your AC unit is running continuously without stopping, this is not a good sign. If the AC runs constantly, the cooling coils inside could freeze over, and the entire system will stop working until the coils unthaw.

An AC unit that is running constantly is unable to keep up with the heat and provide enough cooling airflow into the home. Check your filters and check your outside AC unit, if present, to see if any debris is on or around it

Dirt, dust, and grime that build up over time on filters and on parts of the air conditioner will reduce airflow to the unit, and that will, in turn, reduce the cool air flow you get in your home.

This can cause the air conditioner to work harder in order to pump out cool air because it’s compensating for all this dirt it has to push past, which could result in the unit running nonstop.

Eventually, an AC unit that is constantly running without stopping will stop providing cool air entirely because ice will build up inside the unit. You won’t get cool air again until the ice melts.

What are common fixes for AC not working?

If your air conditioner is not blowing at all or it's blowing warm air, check the breaker box and the thermostat to make sure the circuit hasn't tripped and the thermostat is getting power. You can also check the AC's condensation drain line, as a clog here can cause leaks that will make the AC unit shut itself off.

Further Reading

5 Common Air Conditioner Compressor Problems

11 Ways To Save Money on Air Conditioning

Air Conditioner Parts 101

Air Conditioner Thermostat Wiring

Four Portable Air Conditioner Problems

How to Identify a Leak in Your Central Air Conditioner

How to Remove Ice Buildup on Air Conditioning Coils