Common AC Issues And How To Fix Them

a rendering of the interior of a home

Texas homeowners rely on their air conditioners keeping their homes cool through our hot summer months. So when you wake up and realize your air conditioner isn’t working, what should you do? Calling a professional HVAC technician never hurts, but there are also a few things you can check yourself if you feel comfortable doing so. Below are some of the most common issues homeowners experience with their AC units and tips for dealing with them.

AC Won’t Turn On

It’s a Texas homeowner’s summer nightmare… you turn on your AC and nothing happens. The blower motor won’t even start. In these cases you might end up having to call a technician to come take a look at your system, but there are a few things you can check first.

Tripped Breaker

Check your breaker panel to see if anything is tripped. You might have to check more than one breaker in your home as some homes house the condenser breaker and the fan breaker in different panels. If you reset the breaker and the breaker trips again, leave the breaker off. This could be an indicator that you have an issue and the breaker flipping off is a safety precaution you don’t want to ignore.

Overflow Shut-Off Switch

Clogged drain lines can trigger your air conditioner’s overflow shut-off switch which will sense the backed up lines and turn the system off to prevent damage. Ensure that your drain lines are clear if this switch is being triggered.

AC Cycles On And Off

Another issue some homeowners find themselves facing is an air conditioner that turns off every few minutes. Like an AC refusing to come on, an AC cycling on and off could be caused by a few things, some of which you can check before calling in a professional.


Your thermostat could be malfunctioning. Some thermostats require batteries and will usually alert you when they need to be replaced. It could also be your thermostat placement. If your thermostat is in full sun it could be getting misleading temperature readings.

Clogged Filter

You may not think much of having to change your air filter every month, but not doing so can lead to dirty, clogged filters that affect how your air conditioner performs. If your unit is short cycling, make sure that the filter was changed when recommended.

AC Smells

Homeowners experience various smells from their HVAC systems, such as a mildly dusty smell from a system that hasn’t been used in a while or a light “burning” smell when you first turn on your furnace after summer. However, when your AC starts sending a foul odor into your home regularly, it’s the sign of a problem.

Outside Damage

When your AC starts emitting strange odors, check the outside of the unit to see if there is any damage. Additionally, make sure an animal is not the culprit, either a wild animal that has gotten into it or a pet that may have erroneously gained access.

A Leak In The Unit

The problem creating the smell could also be water leaking into the unit’s HVAC box. Any standing water in the unit can lead to the growth of bacteria, which can cause a variety of unpleasant smells. Make sure to check for any standing water or leaks.

Dirty Sock Syndrome

Yes, it smells just like the name. If your system smells like a well used gym when your air conditioner turns on then you could have dirty sock syndrome. This happens when mold and bacteria builds up on your evaporator coil. Causes could be not changing out the AC filter or your system is collecting too much moisture that builds up on your coil. Once mold and mildew grows due to moisture that builds up over time, dust will collect and feed the mold creating a musty smell.

If you think you might have this issue, make sure that the drain pans under your indoor unit are empty – if they are full, empty them and clear any blockages. Ensure that your air conditioning filter is not too dirty. You can test your filter by holding it up to a light. If you can’t see any light coming through then replace your filter; if your filter is transparent then your filter is still good. Change out your air filter at least once a month.

If you can’t find the cause of an odor coming from your air conditioner it’s important to call a professional HVAC technician right away as some smells can indicate problems that pose health risks.

AC Has Frozen Coil

A frozen air conditioner is one of the most common reasons homeowners experience their AC not coming on or functioning properly. This can be caused by a variety of reasons and there are several steps you can take at home to try fixing the problem yourself.

Low Refrigerant

Your AC doesn’t just use up refrigerant. If you find that low refrigerant is an issue causing your air conditioner to freeze up, it is most likely due to a leak. In these situations, it’s imperative that the leak be found and fixed. If it is not fixed, the problem will simply keep happening.

Restricted Airflow

Restricted airflow can also cause air conditioners to freeze. The cause of restricted airflow could be a couple of things. The most common issue is a clogged air filter. Change your filter and turn off your AC at the thermostat but keep the fan on. Leave the fan running for about an hour or two then turn your AC back on. Make sure you change this if your AC is struggling. If that doesn’t work, visually inspect your ductwork for obstructions and make sure the registers in your home are not blocked.

AC Blows Hot Air

You might find your home warmer than you expected because your air conditioner is blowing hot air instead of cold. When this problem occurs, luckily the issue is often just a simple mix up with your thermostat.

Thermostat Mishap

If your AC starts blowing hot air instead of cold, make sure to double check that you have your thermostat set to “cool.” Homeowners actually find this simple mistake happens more often than you might imagine and correcting the setting is an easy fix.

Additional Problems

If you find that your thermostat is not the problem, you’ll likely need to call in a professional to check out your unit and find what’s wrong. In this case it’s much better to act sooner than later so that the problem doesn’t get worse.

Having issues with your air conditioner that need to be fixed before the full heat of summer hits Texas? Contact the experts at AirOne Heating and Air Conditioning, a local San Marcos HVAC company, to schedule an appointment or inspection today.