Welp, you’re in big trouble. It’s hot enough to fry an egg on the concrete outside and your air conditioner isn’t cooling your home very well. In Arizona, this is almost like a death sentence (a very slow and painful one). Most people will jump to conclusions and say, “Well, obviously you need more Freon!” But honestly, there are several reasons why this happens. To make things simple, we’ll give you a few things you can do right now that may fix this problem. If none of them work, you'll need to schedule an air conditioning technician to diagnose your problem. First things first:  Check the thermostat one more time to make sure it’s on the right settings. Obviously, if it’s accidentally set to “heat” your A/C is never going to come on. But also check the fan settings. If you have it set to “on” then the indoor blower will keep blowing air into your home even when it’s not being cooled. This gives the illusion that your air conditioner is low on refrigerant because it’s blowing cold air sometimes and warm air other times.

Set the thermostat to “auto” so your A/C only blows cold air.  If that didn’t work, then...how to buy a new ac unit Go to your return vent and check the air filter. how much cost to move ac unitDoes it look like the one on the right in this picture?how long do window ac units last If so, change it (it should be changed once a month). A dirty air filter blocks return airflow to your air conditioner. This makes it harder for your air conditioner to circulate the amount of cooled air  needed back into your home. If changing the air filter didn’t work, then... When’s the last time you had the outdoor air conditioning unit cleaned? If the answer is “never”, well you may have found your problem.  We’ve already talked in detail about why you need to clean your outdoor unit at least once a year.

To summarize, the outdoor unit needs to be clean and clear of obstructions (grass, bushes, tree branches, fences)  so it can cool down the refrigerant, which is then used to cool your home’s air. You can clean the outdoor unit yourself using a water sprayer and a special A/C coil cleaner. But doing it properly requires a professional touch. And most professionals will clean it as part of an A/C maintenance visit. (Psst, we have a coupon that takes $40 off an AC tune-up visit) If you’ve cleaned the outside unit, and your A/C STILL isn’t cooling your home well, then you’ll need a professional’s help. They can check for things like low refrigerant, malfunctioning condenser fan, malfunctioning compressor, and so forth. If your air conditioner needs repairing, we have a coupon for $50 off A/C repairs. George Brazil has been keeping Phoenix-area homes safe, comfortable and energy efficient since 1955. Yesterday's high was 106.0F, low of 79.2F, full sun all day.

AC set at 78F, indoor temperature reached about 85F. Today's high was 105.4F, low of 81.1F, full sun all day, now about 102 at 7pm. AC set at 78F all day, temperature climbed steadily through the day, and is now 89F. Is it reasonable to expect an AC unit to maintain 78F in this weather? A properly functioning and properly sized central air conditioning unit should be able to maintain the temperature of your house at any reasonable temperature you select. The amount of cooling available is related to the size of the system, insulation in the house, and finally outside air temperature. From your description I would guess either you don't have a big enough compressor, or you don't have enough airflow through the house. It's also possible the cooling element in the system has become dirty and no longer transfers enough heat from the air into the element. The first thing to check is the return air filters. If they're dirty, your system won't be able to keep up. Also, if the coils are dirty or the refrigerant is low, you will not get efficient cooling.

You can clean your condenser coils (the outside unit) yourself using a jet of water from a hose. Contact a service company to clean your evaporator coils, do a system check, replace refrigerant and do repairs. The amount of in and out traffic you have, shade trees, insulation, type of windows, etc., all play a part in how well your system works. It's been about 100 degrees F here the last couple of days and the thermostat is set at 78 and has had no problem maintaining that. We had the same problem in our house, and we've simply lived with it - having had HVAC companies come out and inspect or evaluate it. They all said the system was in good working order, and was appropriately sized for our house. This year we replaced 3 windows and a doorwall in the first floor of the house, and suddenly we can not only maintain a temperature, but go lower if we want. The air conditioning is doing fine, even though we've still got three old aluminum frame windows upstairs. It was about 80 square feet of window surface that was cheap double glazed aluminum frame, and is now cheap composite framed, double glazed with low-e coating.

So if you've checked the interior coils, the exterior coils, and the system performance and it is still not cooling your house to your satisfaction, it is likely that you need a bigger air conditioner, or you need to better insulate your house - windows might be a big part of that loss. As others have said, if the unit is properly sized for the house, and the insulation is good enough to keep the heat out, and there is enough airflow in the house, the A/C should be able to handle almost any temperature you set it to. There is a point where it gets so hot outside that air conditioners simply can't do anything to get rid of the heat (the outdoor coil temp equals the outdoor air temp). This is extreme though, >110 deg F. You're getting pretty hot, but shouldn't be at that point yet. (Most A/C units will have specs on this. You can try looking up some specs for it online.) You indicated the system is turning on and off, so I don't think it's your thermostat. How cold is the air coming out of your vents?

If the system is working properly, it should be as cold as your fridge. If it isn't cold (not cool, cold), you have a problem. Look at the lines on the outdoor unit. Are they frosting up at all? Is there excessive dripping from your indoor air handler? If your lines are freezing up, turn the system off and call a service company. That means you are probably low on coolant, and running the system without will burn up the compressor. Other problems that would prevent cold air would be crud on the coil, or the fan on the outdoor unit not working properly. If the airflow is weak, then you have an airflow problem. Check the air filters in the system. Make sure your ducts aren't plugged somehow. Check for closed dampers or closed vents. Make sure a duct didn't pop loose somewhere (blowing air into the attic instead of out the vents). Make sure your air handler is blowing air. To get a measure of your air condition performance , try to get a temperature reading, just in front of the inside unit.