is my unit icing-up? I have frost
on the coil and copper tubing.
There are several things that can cause frost on your coil and/or
air flow. Anything that
restricts the airflow through the inside unit will cause frost.
the frost builds up on the coil, the
airflow becomes more and more restricted making the condition
worse.......When the frost is also on the outside pipes next to the compressor, you
a situation where
damage to the compressor can occur.
1. Extremely dirty air filter restricting the airflow through
2. Extremely dirty (clogged) cooling coil restricting airflow
3. System low on freon, causing coil to freeze up.
4. Check your return grill to make sure that it is not being
5. Blower motor overheats and "kicks off" on safety switch.
If you are mechanically inclined, here are a few
The following test is the most important test you can
performed on a system
that is running but not
cooling enough. This test can help determine if your system
on freon or will uncover several
other problems that can cause your system to malfunction. It
a lot about what is wrong
with the system.
Start by inserting a stem type thermometer in the air supply
the temperature. Now
take the temperature of the air entering the return air duct. Subtract
supply temperature from
the return temperature. The temperature difference should be
22 degrees. Make sure there
is no frost on the coil before performing this test.
A dirty cooling coil is a common cause of "Not Enough Cooling
Up" of the system.
You can check to see if the coil is dirty by removing the filter and
at the underside of the
coil with a flashlight. Sometimes a mirror will help you see
You can determine if the blower motor is kicking off on
overload by setting
the thermostat to
"fan=ON" and listening to the blower run. If the motor kicks
a while, then you have a bad
motor. It may take a half-hour or more before the motor
knocks on overload........
In addition, you can feel the body of the motor to see if it is
hot. Be careful when you
touch the motor as they get very hot. Also, turn the power to
off before performing this test.
And, don't forget! Dirt
is the biggest enemy of your air conditioner!
Giving your air
conditioning system an efficient, high MERV rating air filter is
the best thing you can do for your air conditioner. A good air filter will
extend the life of
conditioner because the important parts, like the blower assembly, the cooling
coil, and other inner parts will stay cleaner, operate more
And, as a side benefit of having a good air filter,
your family and you
will enjoy breathing much healthier indoor air. Air
that will be free of dust mites, mold, mildew, dust, pet dander, etc.