The best time to think about how well your current AC is working is when you don’t need it.
Once the heat hits, you’ll be sweating that you didn’t check it sooner.
The best time to look at your AC is in that gap between needing the heater and wanting the AC.
Of course, there’s a world of difference between the AC not working well and not working at all.
When you don’t have money set aside for repairs or replacements, these kinds of problems cause panic, no matter the outside temperature.
Keeping your AC in excellent condition costs, but it also saves money.
Remember that AC counts for 6% of all electricity used in the country.
Like any budget-conscious person, you want to do what you can to be prepared but also avoid total disaster.
The first step is to diagnose what’s not working and figure out your steps from there.
AC Not Working?
The following set of issues isn’t laid out in the most to least probable.
Every AC system is different, and it’s hard to say which one is more likely.
This guide will start you with the easiest to check and end with the ones that land on the work-intensive side.
This way, you at least save yourself some effort if the problem is on the easy-to-find end of the spectrum.
Some issues you’ll be able to fix yourself.
For others, it’s important to turn to professionals to service your air.
Your home won’t get cool if the thermostat isn’t set to a temperature you enjoy.
It’s easy to check a thermostat because it’s right there, no rooting around in the attic needed.
For smart thermostats (especially for multiples in the home) check that they are set to communicate with each other.
Modern smart thermostats work in tandem to provide an overall temp for the home and will adjust based on the area.
Your upstairs will always be slightly warmer than the downstairs of a home because heat rises, so the feel of the home may be consistent even if the numbers on the thermostat are not.
If you have a problem with the thermostats resetting or changing to temps you didn’t choose, check with your power company, they sometimes have the ability to set and control thermostats remotely.
If things are set properly but it feels wrong, check the temperature with a thermometer.
If the reading on the wall and the thermometer are off, your thermostat is reading wrong.
If you see no display or the thermostat turns on and off, replace the batteries.
If your thermostat is connected to the house circuit and flickering, pause in your AC quest and call an electrician to identify the short.
Check Your Electrics
That’s a good segway to this next set of issues.
There are several places where power feeds into your AC system and each can cause a problem.
If the thermostat isn’t connected, that’s an obvious issue.
What’s less obvious is where it might not be connected.
Your options start with checking the breaker box.
You want to make certain that the switch for your AC unit itself isn’t tripped.
From there, check for any other tripped circuits.
IF all the circuits are on but no juice is flowing, it’s time to check your fuses.
There are two fuses connected to the system.
The first is connected to the thermostat itself, even if they have batteries they connect to the unit and that connection can blow its fuse.
The second fuse is the internal fuse of the system itself. If you confirm that all the circuits are on, the thermostat is set, and nothing is turning on, the internal fuse is the likely cause.
Since this fuse is internal to the system, you’re far better off calling in a professional to deal with it.
If nothing starts at all, the fuse is the likely culprit.
If you hear something trying to kick on and fail, that’s more likely a capacitor issue.
The capacitors are battery-like units in the AC box.
Much like an alternator in a car, one provides the run ability, it stores and releases energy to keep the system running along smoothly, converting the wall current into the necessary power for the fans, compressors, pumps and the like.
The other capacitor stores the charge for the initial jolt, again not unlike the starter on a car.
Both of these capacitors wear out over time and when they give up the ghost, they won’t work but they still try.
So you will hear them powering up and trying to discharge but nothing happens.
Filter clogs are easy to check and a good preventative maintenance step.
Filters don’t just affect the quality of air that flows through your system, it also supplies any air at all.
A clogged filter restricts the air coming into your system.
Without any new air coming in to cool down, the AC can’t do its job.
Filter clogs also make the compressor and intake work harder.
These two pieces of equipment create a fair amount of waste heat, if they have to work harder, your system gets bogged down cleaning up the heat it’s generating before it can do any amount of cooling.
Checking a filter isn’t difficult.
You don’t need to understand everything about the HEPA guidelines and filter types.
You do need to know the size and type of your filter if you decide to get a replacement.
Look for patches of discoloration in the filter and then shake it out or blow it out if you have the equipment to do so.
Be gentle, the filter is durable but you don’t want to put a hole in it.
One of the primary reasons you run your air condition system is to beat the heat.
You want the inside of the home cooler than the external air.
Basic physics says this will create condensation.
Most home air conditioners are prepared to deal with this excess moisture.
The droplets that form are blown through the system and collect in a drain pan. This then drains out of the house.
Just like the filter, the drainage line can get clogged.
When it does, no water can get out and the water in the drain pan overflows.
This overflow can cause damage to other electrical systems or give you a musty smell and quality to your air.
Check the system at the main unit.
You will either have a gravity drain, a pan, or a condensate pump (rarely more than one).
A condensate pump can be seen/heard working and you can visually inspect it for water.
For gravity drains, find the exit, put a bit of cloth or cotton up the spout, and look for mold, slime, and debris.
For a pan and a coil, look at the integrity of the metal components.
There should be no rust or holes in the coil or the pan.
Check for Leaking Coolant
Refrigerant leaks make the system work inefficiently and can cause breathing issues for those in the house.
Leaks in the system will make the temperature fluctuate, which makes it hard to tell what’s going on.
Most of the time when the temperature is fluctuating, you are quick to assume it’s just that hot outside or points to a thermostat issue.
Leaks can occur in two ways.
There are obvious sources, such as a hole in a heating coil or the compressor.
These can sometimes be heard hissing near the AC unit’s housing or in vents throughout the house.
Sometimes there is a squeaking sound when holes get bigger.
The refrigerant also leaks through osmosis.
In this case, you lose some of the coolants through the natural use of the system.
Given that the point of an AC system is to make temperatures change, the materials throughout the system change size and shape as it runs.
This creates opportunities for small amounts of refrigerant to leave.
Any leak can seem bad but there are standards for loss rates and their impact on efficiency.
Slowly losing refrigerant over a period of time is expected, so it may be that your ‘leak’ is simply a need for a recharge and no additional repairs are needed.
Larger leaks can affect air quality.
If you notice an acrid quality to your air when the AC is on, turn it off and get service soon to prevent health issues.
Check for Leaking Ducts
Checking for leaking ducts is difficult work because any leak in any duct can cause a system-wide issue.
Ducts run through the walls and ceiling of the house, which also makes them difficult to get to for proper checks.
To start diagnosing a duct leak, you need to seal off all of the ducts in each area of the home.
Closing the duct won’t give you enough of a seal.
You want to tape sheets of paper over each to give a more or less air-tight seal.
Run the AC and check each duct one by one.
Remove your makeshift seal, open the vent and listen to the airflow.
Repeat for each vent in the house.
The further away from the main unit you go, the harder it gets to determine if there is a leak in the duct or just distance involved.
If you get little to know flow from one vent then you know there’s something wrong with the duct.
This could be a blockage from debris or a hole in the duct caused by rodents and insects or even a bend that occurs from the house settling.
Check Fans and Blowers
The last two things to check are rough because the mechanical components, even when working properly and not blocked in any way, can wear out over time.
This makes the issues they cause intermittent, which leads to wondering if you’ve found the right problem source.
Without dedicated tools, there’s a lot of guesswork in air conditioner repair.
Numerous fans exist in most AC systems.
Any of them shutting down will cause the quality of the system to degrade.
Fans can break down in the motors and belts, either from wear or collecting debris.
Visually inspect the blades for dents, cracks, and missing components.
Don’t put your fingers into any part of a fan unless you are certain all the power is off and locked.
Look at the belts and connected drive shafts for missing teeth or worn areas.
Check if the fans can be turned easily or if they have a lot of resistance.
Give the units a sniff for burning components.
Check for leaking grease, oil, or other lubricants in the housing.
The compressor is the second noisest of the components in your system.
It takes stock of refrigerant material and shoves it through the heat exchange coils.
This is most of what cools the air.
Assuming nothing is leaking out, the compressor should have plenty of liquid refrigerant to push.
An overcharged system will give the compressor too much work, and it will burn out.
This is fairly obvious because it will lock up and dispell a fair amount of heat.
An old compressor may not have enough oomph to push the coolant and will stutter as it goes.
A compressor on the edge needs the most attention because it’s an expensive component.
It’s possible that the heath exchange coils need to be purged and charged properly or the compressor tuned.
Compressor issues are nebulous and have the most push/pull in their diagnosis.
Keep Your Home Comfortable
The most important thing to know when you notice the AC not working is how to proceed next.
It can be challenging to figure out exactly where things are going wrong, but identifying the problem is a solid first step.
Always makes certain to shut off dangerous pinch-points like the power and water (depending on your system) to prevent cascading damage.
For more ideas on home repairs and remodels, keep coming back here.