categories | articles | write a review | design your space
log in | sign up ARE YOU A HOME PRO?

Air conditioning unit not working? How to spot the problem

It’s the middle of the summer. The heat wave is steady, which means your air conditioning unit is running constantly. That is – until it suddenly stops working. But the unit itself isn’t old! What could it be? Before you panic and reach for our directory of air conditioning specialists, here’s an idea of what the problem could be!

Troubleshooting air conditioning problems

Like any piece of hardware or appliance in your home, things tend to break down. Most issues with your air conditioning can be easily identified by checking up on the unit yourself and hiring an air conditioning expert to repair it.

Ask yourself these questions to determine if your air conditioning unit needs replacing:

  1. Does the unit need frequent repairs?
  2. Are there temperature inconsistencies?
  3. Is your air conditioning unit anywhere from 10 to 15 years old?

If you answered no to any of these questions, then you’re in luck! There’s a good chance that your unit does not need replacing, but it’s experiencing some issues that definitely need to be rectified by a professional.


Here’s a list of common air conditioning unit issues that could be preventing your A/C unit from operating this summer:

The unit is low on refrigerant

Do you find that your home takes forever to cool? Or, instead of cool air being pumped into your home, the supply vent is actually blowing warm air into the house? Where’s that cool relief you’re in need of?!

If you’re experiencing this problem in your home, there’s a good chance that your A/C unit is low on refrigerant. It’s a liquid agent that cools and dehumidifies indoor air before it’s pumped into your home. When your A/C unit is running low on refrigerant, your unit can’t adequately cool your home. Not only that, but a low refrigerant level is a common sign that the unit itself is leaking.

The Fix: Adding more refrigerant to the unit is not a solution. Instead, it’s important to reach out to an air conditioning expert who can do the following:

  • Diagnose the problem;
  • Repair the leak;
  • Test the repair;
  • Return the refrigerant to a proper level.

This 30-minute video shows you how to identify a refrigerant leak and how to fix it:

Looks complicated, doesn’t it? Refrigerant is a necessary part of the air conditioning unit, one that ensures the performance and efficiency of your unit. That’s why it’s important to leave this fix to a professional. You wouldn’t want to undercharge or overcharge the unit with the wrong amount – or type! – of refrigerant!

The condensate drain is clogged, which shuts down your unit

Your central air conditioner doesn’t just produce cool air, but lots of water. Here’s what happens:

  • When it’s humid outside, water condenses out of the air.
  • Condensation then drips down into a collector pan under the coil.
  • It flows through a drain line to a sewer connection.
This diagram will give you an idea of how the process works.

This diagram will give you an idea of how the process works.

A clogged condensate drain can cause unseen leaks, which is why many of them have an overflow sensor. Once a drain reaches that overflow stage, however, the sensor loses power to the system, therefore a leak could happen and you may not even know about it.

The Fix: Turns out it’s not that hard to clean your condensate drain! This video shows you how to do it in 5 minutes!

But here’s the catch: cleaning the condensate unit should be done BEFORE a leak happens. If it’s too late, then you’ll need to hire an air conditioning expert to conduct a proper repair. Now that is not a DIY!

The unit turns on and off – or doesn’t turn off at all

There’s nothing wrong with keeping your A/C unit when you need some sweet relief from the hot weather. But if you’re trying to turn off your unit to give your energy bill a break and it doesn’t work, then what? What about the times when you want the air conditioning unit to run, but it just keeps shutting down.

If you’re experiencing this problem in your home, it could be that your air conditioning unit is not the right size for your home. The equipment might be too big for your home because it reaches the temperature on the unit too fast and will cycle on and off.

If, on the other hand, you can’t turn off your unit, then there’s a good chance it’s too small for your home because it can’t cool the volume of air that’s in your home, which causes it to run continuously.

The Fix: If your unit won’t turn off, then try turning off the thermostat. If the fan continues to run, then turn off the circuit breaker that’s supplying the equipment.

Then, call an HVAC professional to inspect your unit. They’ll be able to tell you if the unit is the right size for your home!

Buying an air conditioner isn’t as simple as picking out a unit. Take a look at this video for your ultimate buying guide:

The A/C unit is running but not blowing out air

If you can hear your air conditioning unit’s motor running, it’s clearly working, right? But if the motor is running and there’s no cool air coming through, then there could be a problem with the belt that connects the motor and the blower.

The Fix: Get out your toolkit! This repair doesn’t have to be left to a professional.

  1. Turn off the power to the unit. If the air handler is a gas furnace, then turn off the gas and the valve that serves the furnace.
  2. Remove the door on the front of the air-handler cabinet. This will give you access to the blower.
  3. There will be a number stamped on the belt. Take this information to your local hardware store to get a replacement.
  4. Slip the new belt on the motor’s pulley first, then on the blower pulley. It should slide on easily. If the belt seems to fit too tight, then you may have to adjust the motor mount.

Alternatively, the pulley itself could be the problem. Check out this video:

Not a DIYer? Leave the work up to a professional! Take a look at our directory to find an air conditioning expert near you.

The air conditioning unit makes too much noise

While air conditioning units aren’t exactly quiet, if your hear the unit making a squealing sound, your unit is trying to tell you there’s something wrong.

The Fix: Remember that broken belt that doesn’t affect the running of the unit, but prevents air from blowing out of it? Yup, it’s that same belt.

  • It could be improperly aligned;
  • It could be worn out;
  • It could need replacing.


Follow our tips above for replacing the belt in your air conditioning unit! If you’re having trouble with the belt – or any problem with your A/C unit – don’t sweat it. An HVAC technician can get it in proper working order for you before the next heat advisory is issued!

More in Air Conditioning

How to maintain your air conditioning unit to ensure your comfort [VIDEOS

Air Conditioning: Do you know when to replace the unit?

Array ( [0] => 835 )