Air Conditioning Problem?

I'd like to help you identify and repair your air conditioning problem, so let's get started.

First, this page of the air conditioning and refrigeration guide is written for people who are not a/c technicians, and with the belief that your air conditioner was properly and professionally installed.

If your air conditioning problem is that the unit is totally dead and absolutely nothing is happening,

First check the thermostat very carefully to be sure it is turned on.

I have been on service calls, including emergency overtime 1 am calls, where the thermostat simply wasn't turned on to "cool".

If your thermostat is a wall mounted digital type, and it is totally blank, it might be battery powered, and the batteries may simply be dead.

The same with a battery powered remote control.

Replace the batteries.

If the thermostat or remote control stays dead, there's a strong possibility you need a new one.

If the problem isn't the thermostat or remote, check the breaker.

If it is totally over in the off position, someone has simply turned it off.

Before you turn it on, make sure no one is working on the circuit that breaker supplies.

When you've determined it's safe, turn the breaker on.

If the air conditioner runs, cools, and keeps running, you've solved your air conditioning problem.

If the breaker is in the middle, tripped position, turn it all the way off.

Make sure no one is working on anything in the circuit, then turn the breaker on and see if the a/c will run.

If it runs, cools, and stays on, make sure that the indoor and outdoor fans are running, and make sure the evaporator (indoor) and condenser (outdoor) coils are not dirty or blocked.

Listen to the compressor for several minutes.

If you hear the compressor starting and stopping but the condenser fan seems to be running normally, turn off the unit, and have someone check the compressor.

It may need new start components, and then it will run fine.

It might have an open winding, and then you'll need to replace the whole compressor.

If the compressor runs and sounds normal, without any grinding or hammering noises, and the unit is cooling normally, I'd say you don't have a serious air conditioning problem, let it run and don't worry about it.

If your breaker trips again after running several hours or even a couple of days, you have an intermittent air conditioning problem that you should have a good technician check.

The possible problems include:
a bad breaker,
a loose, dirty, or corroded wire connection,
pitted contactor contacts,
condenser fan overheating and stopping,
wires grounding or shorting out,
compressor winding failing,
fan motor winding failing.

If your breaker trips instantly as soon as you try to turn it on, stop.

Have a technician check your unit.

The possible causes include:
a direct short or ground in the wiring, compressor windings or fan windings, or a direct short or ground in relay, contactor, or transformer windings.

One reason not to keep resetting a breaker that trips instantly is that the shorted or grounded wiring could be sparking when you reset the breaker, and it could be a fire hazard.

Here are some examples of additional air conditioning problems that could be caused by repeated attempts to reset a tripping breaker:

Lets say one of the wires going to the condenser fan has rubbed against the frame of the unit, or the fan bracket, or a piece of refrigerant piping, and the insulation wore away, and the wire grounded.

The wire will spark, will very possibly weld to whatever it grounded to, and it will also break; maybe the first time the breaker trips, or maybe the third time it trips.

I have seen grounded wires spark a hole through refrigerant piping, which causes a refrigerant leak, and additional problems.

I have also seen grounded and shorted wires that broke and stopped conducting to the fan, and also stopped conducting to the short or ground.

So now the unit will run and cool, and the compressor will run, but the condenser fan doesn't run,

So the compressor runs at pressures that will shorten its service life, and maybe even break it within minutes.

When the breaker trips instantly, have a technician check the unit.

Could your air conditioning problem be that the unit just doesn't seem to be cooling as well as it should?

Check the indoor air handling unit.
Make sure the filter is clean.
Make sure the coil is clean.
Make sure the blower is clean, and running.
Make sure nothing is blocking the air flow into and out of the indoor coil.

Check the condensing unit
Make sure the coil is clean and that nothing is blocking air flow through it.
Make sure the fan is running.

That's about all you can do unless you're a technician.

I'll be providing detailed troubleshooting guides for technicians on the troubleshooting pages.

If your air conditioning problem is a water leak,

Clear the drain of the indoor air handler.

You can do this by using a wet/dry vacuum cleaner, and vacuuming the end of the drain outside the building.

While you have the shopvac out, open the indoor air handler and vacuum the stuff out of the pan you'll find underneath the coil.

If you can, take a look at the corner of the pan the drain line is attatched to.

If there is debris there, clean it out.

Does your air conditioning problem have something to do with noise?

If it's a humming/buzzing noise, open your unit and look for something loose, or look for a loose panel screw, fan bracket screw, loose pipe clamp, a loose piece of insulation, or even a noisy relay or contactor.

If it's a rattling noise, again, look for something loose in or on the unit.

If you hear your compressor making a grinding or hammering noise, get ready to replace it.
It is failing mechanically.

If a fan is squeaking, the bearings are probably drying out.

Have a technician lubricate it if possible.

If it's not designed with lubrication ports, get ready to replace it.

I hope this page has helped you identify and fix your air conditioning problem, and please, feel free to contact us with any specific HVAC questions you might have, including questions about air conditioning on Guam, or refrigeration on Guam.

For more details on troubleshooting and repair, check our pages on air conditioning troubleshooting and air conditioning repair.