Air Conditioner Not Cooling? This Could Be Why.

Air Conditioner Not Cooling? This Could Be Why.

Summer is going strong! If your air conditioner isn’t, you’re probably frustrated (not to mention extra hot and bothered) and wondering whether a repair will do or if your unit is ready to be put out to pasture.

There are a few things you can check yourself – and a few you can’t. Here are some of the common reasons why your air conditioner isn’t cooling, and whether you can take a look and even resolve the problem yourself, or it’s time to call a pro.

Your Air Conditioner Isn’t On

Wait! Don’t skip ahead just yet. You’re rolling your eyes but this one isn’t as crazy as it sounds. Think about how you usually know that your air conditioner is running. You probably hear the blowing sound and maybe even feel the air coming from a vent. But that doesn’t mean the *air conditioner* is on.

If you have the fan set to on (or even to recirculate), it could very well sound like the air conditioner is on but it sure won’t feel like it. That can lead you to erroneously conclude that something is wrong.

Before you do anything else, make sure that the unit is actually on, that it’s set to cool, and that the thermostat is set lower than the house temperature. Even if the thermostat is set lower than the room temperature, you may want to lower it as much as five degrees to see whether the unit kicks on. If it does, your thermostat could be inaccurate and need a replacement.

Your Filters Are Dirty

Dirty filters can lead to so many ailments, from poor performance to system failure, that we can’t stress enough the importance of regular cleaning or changing (depending on the type of filter you have). When you miss a filter change, dust, pollen, dander, and other airborne pollutants start to build up beyond what your system can handle, and will restrict airflow.

Restricted airflow means poor cooling. But it gets worse, because dirty filters can’t effectively trap particles, which means they begin to build up on your blower fan, motor, valves, or other components, and that can lead to even worse cooling, and unpleasant and expensive breakdowns.

Take a peek at your filters and see what condition they’re in. A typical filter change should occur at least every six months, but if you have pets, do a lot of cooking, have wall-to-wall carpeting, or just a lot of dust, you may need to change filters as often as every month.

Think you have a more serious problem? Get a free estimate now to replace your old AC.

Your Have Low Or Leaking Refrigerant

We hate to break this one to you, but if you have an older unit, which in this case means one manufactured before 2010, then low refrigerant most likely means it’s time for a new unit. Older units generally use the coolant R22 (branded more familiarly as Freon), which was banned by the Environmental Protection Agency (EPA) and phased out.

Once coolant is low in these older units, it’s going to stay low, because you won’t be able to get new coolant to “top it off”. Contact your local HVAC contractor and find out what financing and rebate options are available on a new unit to make the transition as painless as possible.

How do you know if coolant is a problem? If you do have one of those older units, you may have been down this road before, so if you have a known leak, then you probably already suspect the problem.

Otherwise, you can look for signs of leaking coolant, which include a hissing or whistling noise, and ice buildup on the refrigerant lines. For a definitive answer, you’re going to need your contractor to take a look. Unless you really know what you’re doing, this isn’t something you can typically check yourself.

The Condenser Is Dirty Or Blocked

The condenser is that big box that sits outside your home, the thing you usually associate with being the actual air conditioner. Warm air from inside your house is transferred to this unit and then dissipated. If the outdoor unit is very dirty, or blocked by furniture, garden equipment, shrubbery, fencing, or debris buildup, it won’t be able to do its job effectively.

Check the area around your condenser to be sure the unit has plenty of space. It may not be the prettiest thing in the yard, but you can’t cover it up with garden accessories or greenery and expect it to work. Trim plants and clear out the junk if there is any. You could be setting yourself up for major system failure otherwise.

Take a look at the grates and make sure they’re not clogged with twigs, leaves, grass clippings or other debris. If things are looking particularly dirty, brush away any large items and use a hose to gently wash down the rest.

The Unit Is The Wrong Size

An air conditioner’s size is determined by the amount of cooling it can provide as measured in BTUs. The important thing to know is that an air conditioner should be the right size for your space – neither too big nor too small.

If your air conditioner is undersized, it will simply not have the capacity to cool your entire home effectively. If it’s oversized, it will “cycle” too quickly – turning on and shutting off before it can properly cool the air.

If your air conditioner has *never* quite cooled your house effectively – whether it never seems to shut off but rooms remain too hot, or you notice the on-off of short cycles – then it could be mis-sized.

A lot of factors go into sizing, from the square footage of your house, to the number of windows and their orientation to the sun, that it can be difficult to determine this on your own. If you’re never really comfortable and you’re beginning to suspect the unit is simply inadequate to the task, ask your HVAC contractor for an analysis.

The Ducts Are Leaking Or Blocked

Did you know that you can lose as much of 40% of the cool air recirculating through your home just through the ducts alone? And that’s *before* any potential leaks!

Ducts can spring an air leak due to improper installation, or just old age. Either way, you’ll end up cooling the inside of walls, the attic, or just watching the cool air – and your money – disappear.

Over time, ducts can also become clogged, especially if you aren’t diligent about filter changes, have completed a construction project, or just haven’t had them cleaned out in a very long time.

To make matters worse, insects and even rodents can get into ducts and cause blockage and some unhealthy conditions.

It can be difficult to tell if ducts are leaking or blocked, since they’re mostly inaccessible in walls and ceilings, but all things being equal, if your air conditioner seems ok, ducts could be the problem. Have your contractor take a look so you can get to the bottom of the problem.

Don't suffer another day! Get a free estimate now to replace your old AC.

Your Air Compressor Is Damaged

A damaged compressor is never a good sign. It’s the single most expensive piece of your central unit, so if it’s gone bad, check to see if it’s under warranty. If it is, that will help you take action without breaking the bank.

If it’s not, your best bet is probably to consider replacing the entire unit. Chances are it will be more cost effective and set you up for better long term outcomes than just replacing or even repairing only the compressor.

You should suspect the compressor if warm air starts blowing from vents, especially if a lack of cooling is accompanied by rattling, squealing, or even a tripped circuit.

If you notice any of these signs, call a professional immediately.

It’s Too Hot Outside

Wait, isn’t the whole point of an air conditioner to work when it’s hot outside? Yes, but there’s a limit. In general, air conditioners are sized to keep your home cool on the average summer day. What’s average? Well, that depends on where you live.

The average summer temperature in Phoenix, Arizona is a lot different than the average temperature here in New Jersey. A central air conditioning unit is typically designed to keep your home 20-25 degrees cooler than the outdoor temperature.

With an average summer temperature in the ballpark of 90 degrees, you can get your home’s temperature down to about 70. But throw a heat wave in and tack on 10 or 20 degrees, and your indoor temperature will rise accordingly. In short, your unit is not designed to keep your home at a cool 68 when it’s 95 degrees outside.

Before you panic that there is something wrong with your unit, check to see just how much competition it has from a sunny afternoon. It might be doing its job after all.

If your air conditioner isn’t keeping you cool and it isn’t something obvious that you can easily remedy yourself, contact us and let us know. We’re available for repairs, and will provide a free estimate if you need a replacement.