how do you troubleshoot a home ac unit

How do you diagnose AC problems?

The Issue: Your AC Turns on But Isn't CoolingCheck the thermostat to make sure it's working properly.Take a look at the condenser to see if it's dirty or blocked. ... Clean and/or change your filter (We recommend once a quarter.)See if any ice has formed on the coils. ... Check and/or clean the outdoor compressor.

What is the most common problem in AC unit?

AC Running Constantly Correcting an AC that won't shut off helps you protect vital components and prevent your energy bill from skyrocketing. Cause: This is one of the most common AC issues, and it can have multiple causes. You may have a problem with the thermostat, compressor, air filters, or electrical parts.

Where is the AC reset button?

Look for it first around on the exterior of your machine, especially along the bottom edge near the ground. An AC's reset button is typically red and visible, so it should be easy to spot. If you don't see a reset button on the outside, it could be located inside the unit behind the service panel.

Is there a reset button on an AC unit?

Most air conditioning units are equipped with a reset button. These buttons tend to be red and quite small. If you're having a tough time finding it, consult your owner's manual.

Why is AC running but not cooling?

If your air conditioner is running, but not lowering temperatures inside, one issue could be a blocked or clogged condenser coil. When operating correctly, the condenser fan draws air into the outdoor unit through the condenser coil to pull heat energy out of your home.

What causes home air conditioner to stop working?

If your air conditioning unit has stopped working, there are many possible reasons that can explain why. It could be your thermostat, your air filter, a problem with the condenser or compressor, or it may just be time to replace the unit, especially if it's over 10 years old.

How do I reset my outside AC unit?

How do you reset your AC unit?Turn off your air conditioning system using the thermostat. ... Search for the breaker box. ... Shut off your AC unit at the breaker. ... Wait at least a full minute before switching the breaker back to the “on” position.Wait for 30 minutes before turning your unit back on at the thermostat.More items...•

What causes the outside AC unit not to come on?

Usually when the outdoor unit doesn't turn on, it is because something tripped the circuit breaker. When this happens, you can easily reset it after locating the circuit breaker panel. If you find that the AC unit still does not work, the next place to look is the thermostat.

How do I reset my compressor?

Here's how to do it:Unplug your refrigerator. Disconnect your fridge from its power source by removing the power cord from the wall outlet. ... Turn off the refrigerator and freezer from the control panel. ... Reset your freezer and fridge temperature settings. ... Wait for the refrigerator temperature to stabilize.

Where is the AC breaker located?

0:392:41How to Check Your HVAC Circuit Breakers - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou're going to have one set labeled air conditioner. This is for your outside unit. You're going toMoreYou're going to have one set labeled air conditioner. This is for your outside unit. You're going to have a separate one for your inside unit which for the furnace or air handler.

What are the four types of problems in HVAC?

Get Answers to the 10 Most Common HVAC Problems LACK OF MAINTENANCE. ... DIRTY FILTERS. ... PILOT OR IGNITION PROBLEMS. ... THERMOSTAT MALFUNCTIONS. ... MECHANICAL WEAR AND TEAR. ... UNUSUAL FURNACE NOISES. ... BLOWN FUSES OR TRIPPED BREAKERS. ... DIRTY CONDENSER OR EVAPORATOR COILS.More items...

What are the common causes of air conditioner failure?

Damaged Fan Blades, Compressor, Electrical Connections and Contacts. If your air conditioner is over five years old, and cycles on and off frequently your air conditioning system is at risk for premature failure. Annual maintenance will often catch worn and damaged parts before you need emergency repairs.

How much does an AC capacitor cost?

AC Capacitor Cost The cost of an AC capacitor is typically between $9 and $25. Professional installation usually costs between $60 and $200. Replacing this part is a common AC repair cost and is often relatively inexpensive.

What is a common electrical problem in HVAC?

Three common problems wires can encounter are fraying, corrosion and disconnection. These issues can occur when there's a disruption in the flow of electricity. They can also cause other parts of the system to work harder, resulting in breakdowns and other related non-electrical problems. Compressor issues.

Why do we need window AC?

We rely on window air conditioners to keep us cool when temperatures climb. On the “ Consumer 101 ” TV show, Consumer Reports expert John Galeotafiore explains to host Jack Rico how to maintain a window AC unit to ensure cool, clean air throughout the summer.

How much space does an outdoor compressor need?

7. Are plants crowding the compressor? The outdoor compressor for central air needs adequate airflow to work correctly, so make sure there’s at least 2 to 3 feet of space between it and any plants or structures. There should also be 5 feet of clearance between the top of the unit and any trees above.

Why won't my AC turn on?

Whenever this happens, you simply need to reset it on the circuit breaker panel. However, if the AC still does not turn on, you may be having trouble with the thermostat of your AC. In some cases, the problem can be because of the blower belt.

Why does my AC not turn off?

Electrical Problems: AC does not Turn Off. If your air conditioner is repeatedly running and cannot reach a set temperature, it might be the reason for the accumulation of dust and grime in your AC filter. This problem can lead to frozen AC coils; the regular AC maintenance is the solution to deal with this.

What is AC tune up?

Here are a few things that a general AC tune-up includes: 1 Assessment of refrigerant levels 2 inspection of all components and controls 3 lubrication and efficiency of moving parts 4 calibration of thermostat 5 cleaning of filters, condenser coils, and evaporator

What causes an AC to throw up cold air?

If something goes wrong with the airflow, the evaporator coil becomes excessively cold, and a layer of ice builds up on the outside. A faulty condenser will cause the AC to throw warm or no air at all.

What causes a condenser to fail?

Condenser Problems. Faulty tubes and leaks within seals cause condenser failure. After extensive use, these tubes can break, and a professional technician can repair them to make your AC work again. Unwanted particles and debris often lead to condenser problems. The coil of your AC is filled with refrigerant.

What happens if your thermostat is not calibrated?

When you have a malfunctioning thermostat, or it is not correctly calibrated, you will have trouble switching to your AC unit. The dial-type thermostats are more often subject to calibration problems, but sometimes the newer programmable thermostats are also not easy to program.

Why is my AC low on refrigerant?

Low refrigerant means low pressure that eventually results in low temperatures, freezing the evaporator coil. In most cases, a leak is the only reason why your AC would be low on refrigerant. Only qualified and licensed AC technicians can detect this problem, so don’t try to fix it yourself.

Why won't my AC turn on?

Often, if your AC will not turn on, there is simply a problem with the power source. Therefore, the first and easiest thing you should always check when troubleshooting central air conditioner issues is to make sure that the unit has power.

What does it mean when your AC is on but not cooling?

If you notice your AC is on but not cooling the house, this can indicate a frozen evaporator coil. To troubleshoot your central air conditioner in this case, check your refrigerant levels. If they are low, you may have a leak, or the refrigerant may not have been properly charged at installation. If your refrigerant levels are good, ...

Why is my AC making a loud noise?

A noisy air conditioner generally indicates a problem with the fan, fan motor, or even the compressor. If you are able to figure out where the noise is coming from, this can help your HVAC team address the problem. Frozen Evaporator Coils – Finally, frozen evaporator coils are another problem you may face. If you notice your AC is on but not ...

What to do if your thermostat is showing the wrong temperature?

If it is showing the wrong temperature, you may need to calibrate the thermostat. If that does not work, you can also set it to the lowest temperature and see if that kick-starts the system. Although, you should note that setting it this low to try to cool the home feaster is a common home cooling myth.

Can you figure out what the problem is with an air conditioner?

Air conditioner breakdowns are never any fun, especially when you cannot figure out what the problem is. Thankfully, with a few easy tips in mind, you can troubleshoot central air conditioner issues and figure out the problem. Even if you do end up calling in the professionals, looking at the problem yourself can help you describe ...

How long does it take to fix an AC unit?

When central air conditioning service fails during a heat spell, you may have to wait days for an HVAC repair technician or an ac contractor to show up, and you’ll probably pay at least several hundred for the repair. But if you’re comfortable working around electricity and are willing to spend about $50 on parts, you can probably repair your air conditioning service yourself in about two hours and save about $225 on parts markup and labor.

Why Is My Air Conditioner Not Cooling the House?

Set your thermostat to AC mode and lower the temperature setting. If the furnace fan kicks in, the problem isn’t in the furnace. If the fan doesn’t run, try resetting the furnace circuit breaker. If the fan still won’t start, call a pro — the fixes shown here won’t work.

What is the AC unit in a home?

Central home air conditioner service systems consist of two major components: a condensing unit that sits outside your house, and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the AC contactor, the start/run capacitor (s) and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.

How to disconnect a condensing unit?

Open the electrical box next to the condensing unit and pull the disconnect block straight out.

What to do if compressor doesn't start?

If the compressor starts but the fan doesn't, the fan motor is most likely shot. Shut off the power and remove the screws around the condenser cover. Lift the cover and remove the fan blade and motor. Reinstall the blade and secure the cover. Then repower the unit and see if the fan starts.

How to remove crud buildup under a condenser?

Aim your garden nozzle upward into the top of the condenser coil to remove the crud buildup under the lid.

How to turn on AC in a furnace?

Turn on the circuit breaker and furnace switch, then set the thermostat to a lower temperature and wait for the AC to start.

Blowing Warm Air

If your air conditioner is suddenly blowing warm air instead of cold, that can indicate a range of issues, including a broken compressor or a refrigerant leak.

Slow to Turn On

It shouldn’t take several minutes for your unit to kick on after your adjust your thermostat. A delayed cooling could mean it’s time to call a repair technician.

Insufficient Air Flow

Much like a unit that takes a long time to start blowing air, it’s a troubling sign if your air conditioner isn’t blowing enough cool air. If you notice a stark difference from your unit’s typical capacity, consider calling a repair specialist.

Water Leaks

Leaks are never a good sign, whether with your plumbing or your A/C unit. Small amounts could be just condensation. A large pool or discoloration could indicate a more serious issue, like a refrigerant leak.

Unusual Odors

A foul smell coming from your unit could mean lots of things, none of them good — things like mold, mildew or a burned out wire. Those issues call for immediate repair.

Frequent Repairs

This one seems obvious, but if you’re making frequent repair calls, your air conditioner probably doesn’t have a lot of life left in it. At a certain point, you’re better off buying a new unit than funding continued repairs.

High Humidity Levels

High humidity in your home can be especially frustrating if you live in a humid climate. Don’t wait to fix the issue — too much humidity can lead to mold or mildew problems.

Where do most homeowners fail to check when performing AC troubleshooting?

One place most homeowners fail to check when performing AC troubleshooting is the outside unit itself.

Why won't my AC unit turn on?

A loose or frayed wire could also prevent your unit from turning on. Trouble Adjusting the Thermostat. Speaking of the thermostat, glitches within the control center of your air conditioner could also pose a problem. Failure to turn on an AC unit that’s blowing warm air are both signs of a thermostat issue.

What happens if your evaporator coil doesn't receive enough air?

If the coil doesn’t receive enough air or refrigerant levels are low, a layer of ice can develop. In some cases, the coil freezes completely. The result is less cool air coming from the ducts or, in some cases, no air at all.

How does an air conditioner fan work?

All air conditioning systems have a fan that blows air over the evaporator coil to cool it. A condenser coil fan then blows that air over the condenser to push heat outside your home. Like with any mechanism, these fans can wear out, break, or become damaged.

How do you know if you have an AC duct leak?

Holes or tears in the ductwork allow warm air to escape and release into your house. That’s why the first sign that there’s an issue with your AC ducts is uneven cooling.

What does it mean when your thermostat is calibrated?

If your thermostat is calibrated correctly but the AC still isn’t working, check that it’s set to the lowest possible temperature. This should kick start the unit. If not, it may be time to call in the experts.

Why can't air travel through AC ducts?

These ducts pull warm air from the house and carry it to your AC unit for treatment and cooling. If those ducts are dirty, clogged, or have a leak , air can’t travel freely. Some homeowners don’t realize that tears and other obstructions can enter the AC ductwork.

How do I troubleshoot an air conditioner?

No matter what type of system you have – central, mini-split, ductless, or heat pump – there are commonalities between the types of AC systems that our troubleshooting guide covers. If your air conditioning system just isn’t turning on then we suggest you run through a few things before calling in an HVAC expert: 1 Make sure the outdoor breaker fuse is positioned correctly 2 Check your electrical panel for a tripped breaker 3 Confirm that your thermostat is switched on 4 Check for a clogged air filter 5 Check your condensate pump for proper operation

How to fix a clogged AC?

Make sure the outdoor breaker fuse is positioned correctly. Check your electrical panel for a tripped breaker. Confirm that your thermostat is switched on. Check for a clogged air filter. Check your condensate pump for proper operation. If you check these and all is in order then read on for other solutions to AC problems.

Why Is My Air Conditioner Not Turning On?

If your air conditioning system just isn’t turning on then we suggest you run through a few things before calling in an HVAC expert:

Why Is My Air Conditioning Fan Not Working?

If your air conditioning fan isn’t working your HVAC system won’t cool your home.

Why Is My Air Conditioner is Making Noise?

Rattling or banging could mean something has come loose, while buzzing often means you have an electrical issue. Any kind of persistent noise is a cry for help from your air conditioning unit. Turn off your AC and call an HVAC professional to come out and assess your system for issues.

What does it mean when your AC makes a rattling noise?

Rattling or banging could mean something has come loose, while buzzing often means you have an electrical issue. Any kind of persistent noise is a cry for help from your air conditioning unit. Turn off your AC and call an HVAC professional to come out and assess your system for issues.

How to check if a condensate pump is working?

These pumps usually have a test button. Make sure there is some water in the basin and press the test button to ensure it pumps the water out . A failing or failed condensate pump will often trip the furnace so that it won’t run and create a pool of water wherever the furnace is (eg. basement or worse, the attic).

Why doesn't my AC work?

One of the typical reasons air conditioners don’t work properly is a clogged or dirty filter. Follow the manufacturer’s suggestions as to how often to change your air filter. Some are monthly, others every three months, while some are reusable and should be cleaned when they are dirty. One way to determine if a filter needs to be cleaned is to check if any light passes through it. If not, it’s time to clean it. Dirty filters not only reduce the flow of air but can also cause the AC unit to freeze.

What happens if your AC drains?

If it becomes clogged, the drain pan will fill up, and water will leak out potentially causing damage to the AC unit or whatever is around your pan. Breakers or Fuses.

What happens if you don't have enough refrigerant?

If there’s not enough refrigerant, the compressor will run hot and eventually seize. If there’s too much, the refrigerant will return to the compressor, which can cause it to fail. Evaporator coils absorb heat in the air and send it back into the house as cold air using a series of air ducts.

What are the contactors in an AC unit?

In an AC unit, there are contactors for the compressor, the blower motor, and the condenser fan motor. They make an electrical connection that starts the motors and compressor. If there’s arcing and pitting on the contactor, it becomes difficult for electric current to start the motors.

Why does my AC unit freeze?

Dirty filters not only reduce the flow of air but can also cause the AC unit to freeze. Another easy fix is to make sure your thermostat (which controls the temperature setting in your home) is turned on, the inside is clean, it’s level, it’s not being affected by sunlight, and it’s on the correct setting.

What happens if coolant leaks in AC?

When the coolant starts leaking in the air conditioner, the unit will not perform correctly, and the temperature will fluctuate. The location of the leak will affect the cost of the repair so having this examined yearly by a trained AC technician is advised.

Is it bad to have an air conditioner in Florida?

Air conditioning is a necessity in Florida, and life can be pretty unbearable if your air conditioner goes out. Repairs can be costly, so it’s important to make sure your air conditioner is in tip-top shape through regular upkeep. And it’s always a good idea to be aware of some of the more common problems that can arise with your air conditioner.