Air Conditioner Trouble Shooting

Does your air conditioner seem like it runs a lot but barely keeps the house cool? Are you concerned that your air conditioner uses more electricity than it should? Are you worried that the constant stopping and starting will shorten the life of your compressor? Does your air conditioner cool fine but doesn’t stop running? If you said yes to any of the above questions, then we have some answers for you.

Air Conditioner Constantly Runs but Barely Cools

If your air conditioner seems to run a lot more than it use too, you have a couple possibilities to consider. First you may be low on Freon. While the air conditioner is running, take a look at the copper lines leading from the condenser to the furnace. If you see frost, your system may be low on Freon. Call a technician.

Next take a look at your coils. You have an a-coil inside your furnace and a coil around your outside condenser. They should be cleaned at least annually. Dirty coils will restrict air flow causing your compressor to work harder and your system to run longer. For tips on cleaning the coils yourself, CLICK HERE.

If your air conditioner has never cooled like it should, you have two other possibilities to consider. First, the air conditioner may be undersized. Not much you can do about that besides trying to shade your home, block out the sun or replace with a bigger unit. Also be sure that your attic is ventilated so heat can escape. If you have an attic ventilation system (ie Coleman Blend Air or Nordyne VentilAire), be sure it is working properly.

AC Blower
Second, the blower on your furnace may be undersized. If you feel you aren’t getting enough air from your furnace ducts, the blower motor may be the issue. Cold air pushes harder than warm air; therefore, requiring a faster speed. If your furnace only has a single-speed motor, consider changing the blower assembly (pictured right) to a 2 or 3 speed motor. Just changing the motor may not be enough as the manufacturer may require a different size blower wheel. On a 2-speed motor, the slower speed is used for heat, the faster speed for a/c.

Air Conditioner Constantly Runs or Won’t Turn On

If your air conditioner cools fine but doesn’t shut off or turn on, often the culprit is a defective contactor (pictured right). The contactor is found on your outside condenser unit and is fairly inexpensive to purchase and simple to replace. Just be sure your power is first disconnected!! Other issues besides the contactor might be the thermostat and its wires. Wires to the outside condenser unit are generally unprotected and can become damaged. You also have parts inside your furnace that control the A/C. If you are unsure of the problem, call a technician. Also our FORUM may be of some basic assistance.

Using Less Electricity

When an a/c unit starts, it uses a surge of electricity to get it up and running. One way to reduce that surge is to install a hard-start kit. Some universal hard-start kits install simply by connecting two wires to the compressor’s run capacitor. No rewiring required.

Hard start devices (pictured right) assist compressors in starting under very adverse ambient conditions such as low voltage or high head pressures. Hard start devices extends the life of the compressor considerably by bringing them up to speed much more quickly and efficiently. Keep in mind that many newer units may have a hard-start device built into them. But if your unit doesn’t have a hard-start, adding one is a must for energy savings and compressor protection.

Protecting the Compressor

New compressors cost $700 or more. Basically, if your compressor fails and it’s not under warranty, your better off to buy a new air conditioner. Because compressors are so expensive, it pays to ensure they last as long as possible.

One thing you must do to extend the life of your compressor is to add a hard-start kit. For more details, read the previous section on ‘Using Less Electricity.’

The next device you should have installed is an anti-short-cycle timer. This is also referred to as a delay-on-break timer (pictured right). When your compressor shuts off, it must NOT turn back on for 3-5 minutes or the compressor could be damaged. Installing a timer will prevent the compressor from turning back on too soon. Again, many systems or thermostats may already have this timer installed. But if your system doesn’t have a timer, then the next time your power flickers could be very expensive!

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