Living in Arizona means dealing with extreme heat for much of the year and constantly relying on your air conditioning to keep your home sufficiently cool. If you encounter problems with your home’s system, determining the problem, why it’s happening, and how to fix it is crucial for preventing your house from hitting sweltering temperatures. Here are tips on troubleshooting common issues and determining whether you need to call a professional for help.
AC Won’t Turn On
An AC that won’t start can be caused by several issues. It may be dead due to a worn compressor. However, it’s more likely that a less-serious issue is preventing it from running. For instance, the batteries in your thermostat may be dead, which is the first thing you should check. Many newer thermostats don’t use batteries and instead have a common wire (C-wire) that allows them to receive power directly from the HVAC system. In this case, a blank screen on your thermostat, even when you try to operate it, indicates that it isn’t receiving power for some reason.
Another possibility is that a power surge caused your AC to trip the circuit breaker, shutting off power to the thermostat and the rest of the system. You should also check your main electrical panel to ensure your HVAC system’s circuit breaker isn’t tripped.
Resetting the breaker if it’s tripped should result in your AC turning back on within a few minutes. If your AC keeps tripping the breaker, it usually has an electrical problem. At this point, call an electrician. You could suffer significant damage if you try to keep turning it back on. Working on electrical issues yourself can also void your warranty.
Various other issues can prevent an AC from running, all of which you’ll need to have a professional technician diagnose and fix. These can include a failed or malfunctioning control board, a failed contactor, a dead-run capacitor, and so on.
AC Blows Warm Air
If your AC has been running for a long time and your house keeps getting warmer, you should put your hand up to a supply vent and feel the cool air. The air will normally be around 20 degrees colder than the current temperature in your house. Warm or lukewarm air blowing out of your vents is a sure sign that your AC system isn’t cooling as effectively as it should or isn’t cooling at all.
If the evaporator coil freezes, an AC system will start blowing warm air. The ice on the coil prevents the refrigerant from absorbing heat from inside, resulting in the air the system puts out being almost the same temperature as the air coming into the system. If it’s the condenser coil freezing instead, it means the system can’t expel heat outdoors properly, still resulting in warm air coming out of your vents. A coil can freeze for a few different reasons, such as insufficient airflow.
The first thing to check in this situation is the air filter, as a dirty filter can restrict the airflow and quickly cause the coil to freeze. In some cases, a dirty air filter can cause an AC to blow warm air even if the evaporator coil isn’t frozen. Insufficient airflow can also result from an issue with the blower or even just because you have too many vents closed. The evaporator coil will often continually freeze if your AC system is low on refrigerant. This is potentially a more serious problem, as it usually indicates the system is leaking.
Warm air from a single vent or the vents in one part of the house can also indicate that your ductwork is leaking. Another possibility is that a duct in the attic or crawl space isn’t adequately insulated, allowing heat energy to enter the air as it moves through that duct.
Weak Airflow
You may sometimes encounter an issue where the airflow coming out of the vents in one room or part of the house is quite a bit weaker, resulting in that room or area being hotter than the rest. There can also be times when you suddenly start having weak airflow throughout your home, which usually leads to your AC staying on longer than it normally does.
Weak airflow is usually related to one of three things: a dirty air filter, an issue with the blower, or a problem with your ductwork. A dirty filter or malfunctioning blower will again restrict the amount of air coming into the system, which results in the system putting out less air. In some cases, you may still have sufficient airflow in the more central parts of the house, but relatively weak airflow comes from the vents near the ends of your air ducts. If the filter is overly dirty or the blower has major issues circulating air, it can result in weak airflow throughout the house.
Duct leaks often result in weak airflow because some of the air flowing through the duct constantly escapes. Multiple duct leaks or a major leak can also make it impossible for the blower to move around properly throughout the house, resulting in weak airflow in most or all of the rooms. The best way to look for ductwork leaks is to have someone with a camera come and check all of the ducts behind your walls. The issues are likely to be hidden in your home’s structure. However, corroded ducts can become large holes rather quickly.
Frequent Cycling
Another issue you want to watch out for is if your AC starts cycling more frequently than normal and often never stays off for more than 10 minutes. This type of issue is known as short-cycling, and it’s a serious concern due to the additional strain and wear it puts on the system’s motors and other components. The other worry is that short-cycling will often cause your electricity bills to increase significantly. Short-cycling can happen due to issues like the blower running at too high a speed or oversized AC. It can also occur because of an electrical problem or a thermostat issue that frequently causes the AC to turn off too soon.
Strange Noises
Hearing your AC make strange sounds like rattling, squealing, humming, buzzing, hissing, etc., is rarely a good sign. Trying to diagnose why your AC is making a strange sound is something you need to hire a technician for, as different types of noises can happen for various reasons. For instance, humming or buzzing can indicate that the compressor is going bad or the system has an electrical issue. Squealing or screeching usually means that the bearings in one of the motors are going bad or must be lubricated.
As one of Mesa’s most trusted HVAC companies, Honest Air Conditioning is the place to turn if you’re having any issues with your air conditioning. We work on all brands and models of central ACs, heat pumps and mini-splits and will properly diagnose and fix whatever problem your system has. We also specialize in AC maintenance, which is the easiest way to avoid common issues and lower your electricity bills. To schedule an inspection or AC repair call, contact us today.