These are probably the most common Summer-Time HVAC-related complaints! But first things first, please check all of the obvious things (listed below), before scheduling a service-call. Is the thermostat set to "cool" and turned down below room temperature? Is the Power on to the indoor unit? Did you check the breaker? Is the Power on to the outdoor unit? If yes to these, is the outdoor unit running? If no, see if the outdoor unit has a red reset button (most Rheem equipment does, located near refrigerant lines), and push it. If that didn't work, see if you have a condensate pump at the indoor unit. If you do, some pumps have a safety switch that shuts off the outdoor unit if the pump overfills and fails to pump. So check the pump to see if it is working. If that wasn't the problem, back outside at the unit there should be a disconnect box mounted on the wall. These come in many styles. Some have an on-off switch, some have a pull-out plug. Some have a circuit breaker and some even have fuses.

If it has a breaker, make sure it didn't trip. If it has fuses, they should be checked. Caution: High Voltage, danger of electrocution. Please do not attempt this unless you are familiar with working with electricity. For more possible causes as to why your outdoor unit isn't running, please see: If you have checked all of these things, and your unit still isn't running, then you should schedule a service-call. If your outdoor and indoor units are BOTH RUNNING, BUT NOT COOLING, make sure that all windows and doors are closed, your supply and return vents are open - not blocked, and that your air filter is clean. If no problems there, then you should probably turn the air conditioning off and schedule a service-call. Refrigerant flow-related problem - restriction Duct leak in unconditioned space Outdoor coils damaged or very dirtyIs your home’s central air conditioner not cooling your house? Perhaps it’s blowing luke warm or hot air. There are a variety of things that could cause your AC to not cool your home properly.

But for your convenience, we’ll categorize the problems into ones YOU can solve and ones only a professional air conditioning repair technician can solve. Does your AC blow out cool air sometimes and lukewarm air other times? Then the fan setting may be set to “ON” which just runs the fan 24/7—even when the air isn’t being cooled. Solution: Set the thermostat to AUTO.deck over ac unit A dirty air filter reduces airflow into your AC, causing several problems:ac unit is on but no cold air Solution: Check the air filter and change it if it looks like the filter on the rightcheap ac units in florida Here’s how your AC cools your house: the air conditioner’s inside unit (called an evaporator) absorbs heat from your air and then transfers that heat to the outside unit (called the condenser).

But the condenser can’t dissipate heat if it’s dirty or crowded with debris. This causes your air conditioner to struggle to cool your home. This condenser could use some cleaning. Solution: Spray the outside unit with a garden hose on a gentle setting. DON’T blast it on a high setting or you’ll bend the fins that allow airflow to cool the condenser off. Also, remove any weeds growing around the AC unit. Give it some breathing room! Here are just a few problems that a professional air conditioning contractor may need to fix: If the fan motor is bad, then the outdoor unit’s fan can’t help dissipate heat, meaning that the AC can’t cool your house. Refrigerant is the liquid that absorbs the heat from your air. When you don’t have enough, your AC can’t absorb enough heat to cool the air. A low refrigerant level means one thing: you have a refrigerant leak. Signs you have a refrigerant leak include: If you see these signs, turn off your AC and call a professional ASAP.

Running the AC in this state can cause slugging in the compressor and damage it beyond repair. The compressor is the heart of the AC system, circulating refrigerant like blood between the inside and outside unit. If it’s damaged, then the AC can’t cool your air. If there’s an issue with the compressor, then it may need replacing. Unfortunately the compressor is uber expensive.  So unless you have a warranty on it, you’ll probably need to replace an entire outside unit. Did you try solving the problem yourself? Is your AC not cooling your house after checking these possible issues? If you’re in our service area, then contact us for an air conditioner repair—scheduling online saves you 10%.Asking an air conditioning guy why your air conditioner won’t cool is kind of like asking a mechanic why your car won’t run – there are a million reasons.  Since we are asked this question so often though, we do have a few good answers ready to go.  So when asked about “why an air conditioner won’t cool,” or “why an air conditioner won’t cool below 80,” the short answer is that you’ll have to call up your local HVAC technician if you want it done right. 

But then, you’re not on the internet looking this up because you want to drop a few hundred bucks to call one of us out there, now are you?  If you are a return reader to the ASM air conditioning blog, then you know that we are a small, U.S. Veteran-Owned business in Southern California, and like to keep it honest, simple and efficient.  In this article, we will discuss the most common causes for why an air conditioner won’t cool your house properly, including the do-it-yourself troubleshooting tips you can use to get your AC unit up and running properly. With any troubleshooting method, it is important to first understand that safety comes first.  Know your limitations – don’t go poking your head into an attic if you’ve never crawled in an attic before, don’t mess with electricity if you don’t know what you’re doing, and if you have any doubts at any time about what you are doing or whether or not you should be doing it, the answer is “no you shouldn’t.”  

Call the professional out – it’s just not worth it, trust me.  I can’t tell you the hours I’ve spent in an attic trying to figure out what someone was thinking when they did something to their unit.  Fortunately, the most common causes for when an air conditioner won’t cool are pretty simple. If you’ve checked our blog before, then you know that this isn’t the first time I’ve said this – the simplest answer is usually the right answer.  Without going on a tangent about Occam’s Razor, trust me when I tell you that you’d be surprised at how often I get called out to a house only to find out that it was, in fact, the wife that kept turning the thermostat up.  I am far from a marriage expert, as my wife can attest to, but please ask your significant other before you call us out…then make sure that your thermostat has power, is on, is set to auto and displays the desired temperature setting. Also take note of your thermostat’s position in your house. 

Whether you realize it or not, an air conditioner that won’t cool might not end up being the AC unit at all.  Your air conditioner doesn’t kick on because it thinks you are hot, and it doesn’t kick on because it’s hot in your house either – it kicks on when your thermostat gets hot and crosses whatever threshold temperature you have set.  In other words, check the location of your thermostat.  If your thermostat is in the deep dark hallway that is always cool and it is set to 72, then that doesn’t mean your house will be 72 in the front living room with the big windows that get sun all day.  Try adjusting your thermostat to start with, then read: What Temperature Should I Set My Thermostat To? Sit in your chair, relax and take a few deep breaths.  Having any trouble breathing?  Now, take the down comforter out of the closet and wrap it around your face and take a few deep breaths (disclaimer: don’t really).  Is it easier or harder for you to breathe?  Now translate this to why your air conditioner won’t cool – maybe it’s cooling, but it’s having trouble pushing air into your house. 

I say this in almost every one of our articles – your air conditioning filter isn’t really for you, it is a filter to keep contaminants from building up on your AC’s internal components.  The fact that it reduces allergens is just an ancillary benefit.  If you aren’t doing so, change your air conditioning filter no less than once every three months.  It may seem like a pain, or expensive, but your air conditioner works significantly harder when it has to push air through a saturated filter, just like you had to breathe harder through that down comforter.  So hard in fact, that this might be why your air conditioner won’t cool below 80 degrees in your house.  Change the filter and give it a try, then read: Air Conditioning Filter Change. Check the circuit breakers on your main power distribution panel (aka, your circuit breaker box).  Reset all air conditioner related breakers, including ones that are listed as “condenser,” “compressor,” “AC,” “Air Conditioning” and “HVAC.”  

People often times mess this part up – some circuit breakers won’t actually move to the “off” position if tripped.  So to reset them, move the circuit breaker to the “off” position, wait a second, then switch it back to “on.”  Do this for all of the applicable breakers. Next, go to the air conditioner itself (if it is on the roof, careful of loose leaves, etc. and don’t go up unless you know what you are doing).  If you have a “package” AC unit, then there is only one component, usually on the roof.  If you have a “split” AC unit then you have one piece outside and one inside.  Go to both and look carefully for another set of circuit breakers.  Some models have them, and some don’t.  If you see them, reset those too.  If one of these circuit breakers throughout this process keeps tripping off (making an obvious sound), then read: Air Conditioner Circuit Breaker Keeps Tripping for more information on troubleshooting this malfunction.  Don’t just keep resetting it!

If you have a split unit (see: What is a Split Air Conditioner?), then the condensing unit (or “condenser”) is the piece that’s locked outside.  For a package unit, it is all together in one unit outside (hence, “package”).  Either way, go to it.  Check it for debris.  Any leaves, branches, dirt mold and grime that have collected on it needs to be removed.  WARNING – don’t stick your hands inside that thing yet because it could kick on and hurt you!  Either call a professional HVAC specialist, or for the veteran do-it-yourself types, start by removing power from the unit using two different methods (use both, not just one): turn the thermostat to the “off” position, AND turn off the applicable circuit breakers (in HVAC, we ALWAYS turn a unit off at two separate locations for safety – that way, when someone comes along and says “oh, the thermostat is off” and turns it on while your arm is elbow deep in your condenser…get the point?).  Another word for the wise is to turn off all the power, not just the air conditioning breakers. 

Who said that whoever labeled those circuit breakers did it right?  In my experience, it’s about a 50-50 chance that it was labeled right – be safe and just turn off all the power why you do this.  After you turn them off, wait a few minutes just to make sure it doesn’t kick on, then go to work. Ok, enough motherly guidance.  Remove all large pieces of debris, then clean the heck out of that thing with a hose and a brush.  These coils are the exact location that your air conditioner releases the heat from inside your house into the outside air, so make sure they’re cleaned well.  Replace all safety panels, etc., and turn the power back on, as well as the thermostat. See if your air conditioner cools your house now.  If it doesn’t then you’re out of luck.  It is time to call the HVAC pros out.  If you live in Southern California, we ask that you keep us at ASM in mind, but chances are that you don’t live here.  Either way, here is an article I wrote on How to Choose a Reputable HVAC Contractor.

Like I said about the mechanic and your car at the beginning of this article, there are a million reasons that your air conditioner won’t cool, but you’ve honestly done everything that you can.  The number one thing that you can expect your air conditioning technician to do is to hook up to your system and check the refrigerant levels (either R-22 or R-410).  If he notices that they are low, he might opt for a Nitrogen Leak Check, where he will pressurize your system with nitrogen and wait for a while.  Then when he checks the gauge later he can tell if some nitrogen has leaked out.  If so, you have a leak and can go from there.  If not, then your Freon was probably just low.  He’ll top off your refrigerant and go from there.  Either way, call in the pro and see where it goes. I hope this has helped.  In the end, when your air conditioner won’t cool it can be frustrating, but it isn’t then end of the world.  Follow the troubleshooting steps above and go from there.