“Why is My Air Conditioner Not Blowing Cold Air?” [FAQ]

May 14, 2021

It’s a common question we hear from California homeowners in summer, “Why isn’t my air conditioner cooling my home!?”

We’ll help you troubleshoot this annoying problem. To do that, we need to ask you a few questions to help pinpoint the cause of the problem.

So, our first question is…

Is air coming out of the supply vents, but it’s just not cold?

If no air is coming out of your supply vents at all, skip to the second question. If you answered “yes” to this question, follow these steps:

1) Check the thermostat fan setting— Does your air conditioner run cold air sometimes but hot air other times? Make sure the fan setting is set to “auto” not “on”, which will cause your AC to blow air even if it’s not being cooled.

2) Check your air filter— If the air coming out of the supply vents is weak and not very cool, check to see if the air filter is dirty and change it if necessary. A dirty air filter blocks airflow to the air handler. Out of air filters? Here’s our guide on selecting the right home air filter.

3) Check the outside AC unit—Is the outside unit covered in dirt, dust or grass? Clean it. Is it being smothered by a tree branch or bush? Trim them back to give the outside unit breathing room. Is the outside fan not working? A professional needs to fix it. Otherwise, the outside unit can’t cool down refrigerant to cool your home’s air.

If none of these helped, your AC may be low on refrigerant. However, this is caused by a refrigerant leak, which you’ll need a professional’s help to find and fix.

Is your air conditioner not blowing any air?

If no air is coming through your supply vents and the AC unit isn’t working at all, follow these steps:

1) Check your thermostat temperature— Make sure you’ve set the temperature setting at least 5 degrees below your room temperature.

2) Make sure the thermostat is set to “Cool”— Seems simple, but you never know if one of your family members (or the dog) accidentally set it to “Off” or “Heat” by accident.

3) Check the air filter— If an air filter gets too dirty, it will completely block airflow and freeze the inside unit. Change the air filter if it’s dirty.

4) Check that electricity is going to your air conditioner—This means checking service switches that are:

• By the compressor in the outside AC unit
• At the air handler in the inside AC unit (This is typically where your furnace is)
• At fuses or circuit breakers in the electrical panel

If any switches are set to “off”, then there may be a problem with your air conditioner.

For example, an AC with a water sensor switch will shut down if it has a clogged condensate drain line and water spills into an overflow pan. Long story short, your AC needs to be shut down to prevent water damage to your home.

Also, your AC may also be overheating, causing the air conditioner to pull in more electricity than the circuit breaker can handle. So, the circuit breaker cuts power to your AC. If the circuit breaker keeps cutting power after your AC runs for a while, don’t ignore it. It’s trying to tell you something is wrong.

Call a professional to figure out why this is happening.

If you need help finding any of the switches we mentioned, ask our experts for help.

Get quick AC repair in Northern California

If your AC still isn’t cooling your home and you live in the East Bay, San Jose, or Sacramento areas, contact Service Champions Heating & Air Conditioning for expert AC repair.