Why Is My AC Not Blowing Cold Air?

Why Is My AC Not Blowing Cold Air

Why Is My AC Not Blowing Cold Air?

Your AC is not blowing cold air because there’s either an airflow issue, a refrigerant issue, or a mechanical issue. Most air conditioner problems have a relatively straightforward solution that you can enact to get your central air conditioner up and running again.

For more serious problems, you will have to call on the services of a trained HVAC contractor, who will likely be able to provide you with a solution that suits your needs and bank balance.

In this article, we provide you with a few troubleshooting tips that you can try before you call in the professionals to help cool your home and get your air conditioner blowing cold air in no time!

DIY Solutions When Your AC Isn’t Blowing Cold Air

🧰 The System’s Air Filter Is Dirty or Clogged

Woman holding pleated air filter

All HVAC systems come equipped with air filters that remove particles from the air before the conditioned air is circulated around your living space.

The air filter is designed to be porous enough to let through sufficient airflow.

Over time, the clogged filter will pick up enough dust and other particles to become blocked or clogged and completely block airflow.

This is a problem because a dirty air filter can prevent your air conditioner system from blowing cold air since not enough warm indoor air enters the air handler.

This is also one of the reasons for a frozen evaporator coil.

Without the hot air to transfer cold temperatures generated by the compressor, the evaporator coil will often freeze and stop generating cool air. 

If your air conditioning is not cooling enough, you should inspect your air filter to see if it needs cleaning or replacing.

Standard practice says that you should replace your dirty filter with a new one at least every 60-90 days

You will find it within your indoor air handler unit.

Replacing your air filter regularly is also a great way to improve indoor air quality.

🧰 Check The Thermostat Settings

checking thermostat settings

Another simple fix you can apply to your air conditioner is checking the thermostat.

We commonly hear of complaints caused simply by air conditioning systems set to the wrong setting.

Ensure that the thermostat is set to cool, not just the thermostat fan setting.

If this does not work, you can try replacing the batteries in the thermostat and wiping the temperature sensor to remove any dust that may be causing inaccurate temperature readings.

Now, this sounds really simple, but it could just be a circuit breaker that has tripped

Find the electrical panel and check it. Reset it and check the thermostat again.

🧰 Blocked or Clogged Registers

Floor Vent

🧰 Blocked Cold Air Return Registers

Before the air gets to your furnace, it goes through cold air return grills on your floors or walls.

If any of these registers are blocked, your central AC unit will act like it has a dirty filter and freeze up.

Many people place boxes and furniture over the registers blocking air flow.

Ensure all registers are clear and follow the instructions found in this article’s dirty air filter section.

🧰 Blocked Supply Air Registers

We see this all of the time in the HVAC industry.

Homeowners place rags in a supply air register because they want less air in that space or more air elsewhere.

This usually isn’t a huge issue, but the indoor evaporator coil will freeze if too many registers are blocked.

🧰 There Is a Problem With the Condenser Coil

cleaning ac condenser coil

The Condenser is responsible for dispersing the heat that is absorbed from the indoor environment and is part of the outdoor ac unit.

Since the condenser is located outside, it commonly becomes surrounded by leaves, foliage, and other debris.

This debris can obstruct its ability to disperse the heat from inside.

In this case, you should take action to clear a space around the outdoor air conditioner unit, cutting back any overgrown plants and sweeping up leaves and dust.

🧰 Drain Pipe Clogged

Condensate Drain Line

A clogged drain on your AC system will cause condensation to back up into the evaporator drain pan.

This increases the humidity level, making it harder for your AC unit to absorb heat energy from the air.

The key indicator of a clogged drain is water on the floor around your furnace.

If this happens to you, call a professional HVAC contractor or follow the instructions found in our article on How to Fix a Clogged Furnace Condensate Drain.

When to Call an HVAC Company

🧰 Faulty Air Conditioner Compressor

ac compressor cycle

The compressor in your condenser unit is possibly the most important part of your air conditioner, being able to effectively provide your home with cool air.

It is responsible for pumping the refrigerant from the inside to the outside unit so that heat exchange can occur.

Located in the outdoor condenser unit, the compressor is one of the most expensive components in an AC system.

It has an average lifespan of 12-15 years, although this can be lengthened or shortened depending on the amount of use it sees and the maintenance it receives. 

Replacing a faulty compressor is not a job for amateur DIY-ers. 

Installing a new one requires specialist skills and knowledge about refrigerant systems, so it is best to call in the help of a highly rated HVAC company.

🧰 There Is a Problem With the Evaporator Coil


If your HVAC system doesn’t include a clean evaporator coil, then it definitely won’t be able to blow cold air.

If you have a home with pets, or if you know that you’re not very good at regularly changing your furnace filter, then you might have a dirty evaporator coil.

The key indicator is a frozen evaporator coil and frozen pipes.

This can also be caused by a blocked filter or a refrigerant leak.

If you find that your evaporator coil is frozen, set your thermostat to the “OFF” position and the fan to the “ON” position.

This will help to melt the ice.

Keep in mind that if you don’t fully melt the ice, it will freeze up again, so it’s best to leave the AC off for at least 24 hours.

If it freezes again after changing the filter then you either have a refrigerant leak or a dirty evaporator coil.

In these cases, you’ll need to call in a pro.

🧰 Air Conditioner has Leaking or Low Refrigerant (or Freon)

Heat Pump repair with vacuum pump

Refrigerant or Freon, as commonly known, is the liquid that is responsible for absorbing the heat in your home and transferring it to the outdoor environment.

Normally, the compressor and refrigerant lines form a sealed system that will not require you to adjust the levels of refrigerant in the system.

However, if you do not maintain your system, the refrigerant lines can freeze and crack, causing a refrigerant leak.

Low and leaking refrigerant levels can also cause ice buildup.

If you have a refrigerant leak, you should immediately call an HVAC professional to repair the refrigerant lines and top up the system with a refrigerant charge.

If you do not do this, you may cause lasting damage to the compressor.

🧰 Broken Air Conditioner Condenser Fan

AC Condenser Fan

The condenser fan is responsible for blowing air across the condenser to cool the refrigerant in the condenser coil. It is located in the outside ac unit.

If this fan is not working properly, it can produce insufficient cold air.

If the air flow is reduced, you will get ice buildup on the condensing coil.

Although replacing a condenser fan is a relatively simple procedure for a trained HVAC professional, the number and complexity of the electrical components it contains means that it is inadvisable for an amateur to attempt.

If you want to learn more about your AC fan, check out: AC Fan Not Working? The Homeowners Guide to Cool Air

🧰 Damaged and Leaking Air Ducts

residential ductwork

Well-functioning air conditioners rely on an airtight seal in the duct system and around the evaporator coil.

If, for any reason, this seal breaks, it can result in a loss of suction which prevents the fans from effectively blowing warm air through the AC system evaporator coil.

Air duct leaks also allow cool air to escape from the central air conditioning system, which can have a negative impact on its overall cooling capacity. 

As most of your ductwork will be concealed between the floors of your building and in the walls themselves, locating any suspected leaks can be tricky.

It is almost impossible to detect a leak by the naked eye unless the crack or hole is of significant size.

Instead, something called a duct test needs to be performed.

A duct test requires a specialist duct testing device to measure how much air is escaping the ductwork.

This procedure is usually performed by professionals who are trained in the practice of duct testing and repairing damaged ductwork.

Final Thoughts on Your AC Not Blowing Cold Air

Phyxter Approved Logo on Service Truck

There are many reasons why to your question,”Why is my AC not blowing cold air?

Some potential causes can be addressed independently without needing to call in professionals. 

If your AC system is undersized and not cooling your home correctly, you will definitely need the help of an HVAC pro.

However, if you have any of the more serious issues listed above, you will need to help a professional HVAC contractor to resolve them for you.

Contact Phyxter Home Services when you need an HVAC professional to check out your home’s AC.

Check our AC Services page for more information and see if we service your local area.

We have local and independent contractors who are experts at fixing air conditioners and can get them running efficiently in no time.

So, don’t wait until it’s too hot.

Schedule an AC service with a professional technician today and fix the problem of your AC not blowing cold air.

Dealing with other common AC problems? Check out: Top 18 Common AC Problems and Solutions.

Russell Jones

Russell, a native Australian and VP of Operations at Phyxter Home Services, is also part-owner of Vernon Air Conditioning, Plumbing, and Electrical Services. When he's not busy with work projects and renovations, Russell enjoys putting his vast knowledge of home improvement to good use by sharing his tips and tricks.

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Phyxter (pronounced Fix-ter) is a national home services brand specializing in Residential HVAC, Electrical and Plumbing solutions.

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