An air conditioning system is made up of several small, occasionally invisible moving parts. Like any other complex machine, an AC unit can’t last forever—at some point, hopefully, in the distant future, it has to be replaced. But how can you tell if your AC system has given you all it can give and is close to breathing its last?
Here are some possible signs that—especially if many are occurring at once—may mean your AC system is beyond the fixing stage and needs to be changed out.
It blows warm air
Perhaps the most telltale sign that your air conditioning unit is on its last legs is its blowing hot or warm air out of the vents, rather than the cool air you’d expect. Granted, warm air could also be the result of a bad thermostat setting, constricted flow, or an air filter that needs to be changing, among other things.
It blows less air
Restricted airflow is another warning sign that your AC unit may need to be replaced. This could also be the result of a clogged air filter or obstructions in your air ducts, but it could also mean your unit can no longer generate the energy required.
The thermostat doesn’t work
If you’re positive the temperature in your house is nowhere close to the setting you’ve made on your thermostat, it could mean that your system is hopelessly out of sync. Alternatively, you may just need to replace or clean the thermostat.
The outside unit is very noisy
Mechanical breakdowns coming from the depths of your outside AC unit, such as a malfunctioning fan or compressor, could result in a series of unbearable noises when the unit’s operating. Humming or buzzing sounds may indicate a problem with the electrical wiring.
It smells bad
Any kind of odor that coming from your air conditioner is a sure sign of trouble. Excessive condensation may have led to the formation of mold, mildew, or fungal colonies. Heavy stink may be the result of bad evaporator coils or stagnant water. Two particular smells require immediate attention: a burning smell may indicate a dangerous electric fault, and an odor resembling sulfur or rotten eggs may indicate a gas leak. Shut your AC down at once.
It’s too humid
In addition to keeping a cooler temperature, central air is intended to control moisture inside your home. If your house is insufferably humid, or your air conditioner is taking too long to make it less humid, that could be a sign that it’s time for a new unit.
Refrigerant leaks in various spots around the air conditioning unit—most often around soldered joints or connections—are usually signs that major work is needed.
It still uses freon
Speaking of, the federal-mandated phase-out of R22 refrigerant—commonly known as freon—is supposed to be complete by the end of 2020. If your AC system only works with freon, it needs to be replaced with one that uses R410a refrigerant (which is more effective anyway).
Your electric bill is higher
Of course, if your AC unit needs more energy to work properly, you’ll pay more for that usage on your utility bill. Check to see how much your utility charges have increased, especially if you keep a regular schedule of turning your AC on and off. If it’s significantly higher, you may need a new system.
It’s more than 10 years old
Air conditioning units are like every other appliance in the world: they simply weren’t built to last forever. Eventually, they give out. With meticulous upkeep and attention, the lifespan could be as long as 15 years. But if your unit’s more than a decade old and you’re noticing a lot of the above issues happening, a full replacement could be what you need.