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Home > HVAC > 4 Reasons Your Air Conditioner Won’t Work

4 Reasons Your Air Conditioner Won’t Work

July 28, 2017

4 most likely reasons why your air conditioner won't work

Air conditioner problems are always a hassle, but in the summer they become more than a hassle. Case in point: the National Weather Service issued an excessive heat warning for Los Angeles county recently. According to their report, “Dangerous warning level heat is expected today through Saturday, when high temperatures between one hundred and
five and one hundred and ten degrees will be likely for many interior sections of Southwest California.”

One hundred. And ten. Degrees. Temperatures shouldn’t have that many digits in them. You’re going to need your air conditioner, badly. If it’s suddenly ceased functioning, you’re probably frantically looking for ways to stay cool before you get cooked. Don’t give up yet! Usually, when an air conditioner stops working, there’s a simple reason why and an even simpler fix. Before you commit to that log cabin in Alaska, see if any of these four super common problems is your culprit.

broken thermostat
Thermostat Malfunction

If your air conditioner won’t start at all, this is the first place you should check. If your thermostat has stopped working, your air conditioner won’t turn on even if there’s nothing wrong with it! First, simply set the thermostat to the right temperature and setting. If you want to test it, set it for a low temperature, so that the AC unit would start right away. Make sure you set it to “cool” and not “heat”!

If that doesn’t work, either replace the thermostat’s batteries or look for a dedicated thermostat or AC switch on your circuit breaker. A blown fuse might deactivate your thermostat or your air conditioner unit itself, especially if there was a storm recently.

AC compressor
Flipped Switch

After thermostat problems, the most likely explanation for an air conditioner unit that won’t turn on is… you haven’t turned it on! Depending on your home’s setup and the model of your unit, there could be a couple different “off” switches controlling power supply to your air conditioner. If someone accidentally flipped either of these, then your air conditioner won’t activate regardless of the thermostat’s setting or its state of repair.

First, look for an emergency shut-off switch near the outside condenser unit. This switch is usually housed inside a metal box to protect it from the elements. Make sure you flip the switch “on”. Next, look for a normal-looking electrical switch near your HVAC unit. Your air conditioner might connect to one of these switches, just like your furnace probably is. If you find a switch and you don’t know what it does, turn it on and try running the AC.

air filter
Clogged Filter

This could be the problem if your air conditioner won’t turn on, but it’s even more likely if it runs but doesn’t cool. It’s easy to forget to replace or clean your HVAC air filters. Your air filter is inside your house, usually near the return air duct or blower compartment.

Air filters work by “catching” dirt, dust, and other contaminants in your home’s air as the HVAC cycles the air through it. Over time, air filters become clogged with the contaminants they’re catching. Clogs reduce effectiveness and may eventually cause an airflow problem. If the AC won’t work properly, one of the first things you should check is your air filter.

Dirty AC condenser
Dirty Condenser

The air condenser unit is the box-shaped air conditioner unit outside your home. This unit contains the air compressor, cooling fins, air transfer tubes, and fan. The fan sucks air into the unit and through the cooling fins. The compressor contains a special coolant that it applies to the cooling fins and tubes. Air cools as it passes by the cooling fans and then enters the vents through the tubes.

As your condensers’ fan sucks in air, it may also pull random outdoor materials onto the unit. This stuff gets lodged in the condenser fins, where it blocks airflow just like it would on the air filter. Turn off the power to the condenser unit and thoroughly clean it. Start with the condenser fins and work your way into the inner unit. Be careful not to damage anything inside the condenser while you’re cleaning.

If you’ve tried each one of these quick fixes and your air conditioner still won’t work, it’s probably because there’s a more significant problem with either your condenser unit or your ventilation system. If that’s the case, give Mike Diamond a call ASAP and we can get it working again fast. Stay cool!

Filed Under: HVAC

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  • Schedule Service
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      • Pipe Repair and Replacement
      • Leak Detection and Pipe Leak Repair
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