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Kilowatt Heating, Air Conditioning and Electrical Blog

The Most Common Air Conditioner Problems

Air Conditioning System Not Cooling Properly

There are several common problems that could cause an air conditioning system in Los Angeles not to cool properly:


Oftentimes air conditioning problems are a matter of low refrigerant charge, which means the AC unit could be leaking. The solution would be to find the leak, repair it, and recharge the system.

Thermostat Issues

Check your thermostat to make sure it’s properly set and that it is reading the correct temperature.

Drainage Problems

Sometimes the air conditioner’s condensate drain gets clogged and needs to be flushed out. Things that cause air conditioning condensate drainage lines to clog up are pet fur, dust, or something coming into the drain from the outside such as plants or dirt.

Dirty Filter

Many heating and cooling problems in Los Angeles can be solved by changing a dirty filter. Our Kilowatt main office is right at the interchange of the 405 and the 101 freeways in Sherman Oaks so we know how dirty the air in our city can be.  The air closer to freeways has been shown to carry more particulates. That makes sense, but it may surprise you to learn that indoor air is 30-40% dirtier than outdoor air! So HVAC filters in Los Angeles get clogged more frequently. A clogged filter restricts airflow through the AC system, decreasing it’s efficiency and reducing its ability to effectively cool the air.

photo 4AC Unit Not Turning On

If your air conditioner is not responding at all, there are a couple of issues that may be the cause:


If your thermostat is not working it may need new batteries, it could have a loose wire, or it may need to be replaced entirely.

Electronic Control Failure

Sometimes the electronic controls for the fan or the compressor wear out. The frequent turning on and off the the equipment can cause that tiny part to fail and need to be replaced.

Not Enough Air Flow

Sometimes the air conditioning is running and cooling but the flow of air coming out of the vents is weak and ineffective. Causes could be:

Problem with the Ducting

We have seen leaky ducts that have been crushed or broken by other workmen, rodents, or storage boxes pushed into an attic and accidentally into duct-work. Sometimes ducting becomes clogged or constricted.

Clogged Filter

Problems stemming from a dirty filter are so common we have to say it twice. A filter is usually placed inside the return air grill which is bigger than the other grills in your home. Sometimes a filter is near the blower motor of the furnace. All heating and air conditioning systems should have a filter to, at the very least, keep the interior components of the equipment from getting dirty. when filters get dirty they restrict the airflow and cause several different issues. Weak air flow is one of those issues.

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