When our homes run smoothly, we don’t question it. But when we experience power outages or central air conditioning problems, we realize just how dependent we’ve become on the mechanics of modern life. Diagnosing an air conditioning system often requires an air conditioning repair technician because there are so many variables to why your unit has stopped working or operating at peak performance.

Here are a few things you can check before determining if a service call is in order.

10 Common A/C Problems & DIY Troubleshooting

1. Indoor blower not running.

Again, be sure the switch to the air conditioner air handler is in the “on” position. Sometimes there’s more than one switch, one right near the unit and another at the entry to the room where the equipment is located. Make sure that the blower compartment cover or door is properly closed or an interlock switch may be keeping the system “off.”

2. Little or no cool air coming out.

Check that your air filter has not become blocked with dirt and debris preventing air from coming out of the registers. Usually the air filter is right at the air handler or blower unit, or your air filter may be installed behind a grille covering a central warm-air return that sends air back to the air handler.

3. Blower fan won’t start.

If the indoor air handler blower fan itself won’t start, check for lost power. Check for a blower fan that is loose on the motor drive shaft or for a broken or lost blower fan drive belt on pulley-driven blower systems.

4. Blocked condensing coil.

A blocked outdoor compressor can cause the unit to overheat, stop running or become noisy and work poorly. The simplest solution, of course, is to remove the blockage, whether it’s overgrown shrubs or too close enclosure.

5. Tripped motor.

Be sure that the service switch and the air conditioner indoor power switch, fuse or circuit break are all in the “on” position.

6. The air conditioner has stopped working completely

Take a deep breath and remember that oftentimes the simplest explanation is also the most plausible explanation.  If your air conditioner has stopped working, it is likely because it either has no power supporting it or something told it to stop working.  Therefore, start by looking for any tripped fuses or see if someone has sneakily turned the unit off.

7. The air conditioner compressor switches itself off

Another reason your air conditioner may shut-off is due to high pressure. On an extremely hot day, the high-pressure switch of your air conditioner may trip, shutting off the compressor. You may be able to fix this problem by flipping the circuit breaker off, cooling the air conditioner compressor with water from a hose, and the switching the breaker back on. (Also, keep in mind that this year Xcel Energy launched its ‘Saver’s Switch’ program.  This program, designed to save energy, will automatically and briefly shut down air conditioners during peak demand times.  If you are one of 330,000 who signed up for this program, you may have come home during an ‘off’ cycle.)

8. Your air conditioner is making a lot of noise

Dirty or obstructed fan blades are oftentimes the culprit of noisy air conditioning units.  See if this is the case by turning off your unit completely and checking the unit blades to ensure they are clean and unobstructed.  If you do see dirt or an obstruction, follow a tip from our Spring Air Conditioner Checklist and brush away any accumulated dirt or clean the unit with light water pressure from a garden hose.

9. The evaporator coils have frost build-up

Frost can build up on an air conditioner if you allow it to operate when the external temperature runs below 60 degrees.  Switch your air conditioner off, and leave it off, until the frost completely melts away and the external temperature rises above 60 degrees.  Keep a close eye on your unit for the next several days for a recurrence of this problem.

10. Refrigerant is leaking from your air conditioner

Low air pressure followed by the release of unpleasantly warm air will oftentimes be an indication of a refrigerant leak.  If you suspect a leak, the best advice we can offer is to call a professional immediately, as the leak could be anywhere in your line or unit coils. Luckily, the repair will oftentimes be as simple as soldering a leak in your line or replacing a coil, meaning you will be back up and running in no time.

Most refrigeration problems in air conditioners are electrical, not mechanical. When troubleshooting your air conditioner, it’s worth checking out switches and controls before replacing more costly components If your air conditioning system is still not working, or if the A/C system is running but cool air is not coming out of the supply registers, you probably need to call a service technician.

Contact Welter Heating

If you need service on your air conditioning system, contact us online or call Welter Heating and Air Conditioning at 612-825-6867 for service or installation.

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