5 Most Common Central Air Conditioner Problems

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The above video will help you identify some of the basic indicators when troubleshooting an air conditioner problem.

When a central A/C unit fails during a heat spell, you may have to wait days for a technician to show up, and you’ll probably pay at least several hundred for the repair. But if you’re comfortable working around electricity and are willing to spend about $50 on parts, you can probably repair your air conditioner yourself in about two hours and save about $225 on parts markup and labor.

These tips will help you with the most common “low cooling” and “no cooling” problems. You’ll need an inexpensive multi-meter, a voltage sniffer, an assortment of screwdrivers and a socket set.

If these fixes don’t work, at least you’ve covered the most common failures, and your service guy can concentrate on finding the more elusive problem. Plus, with the new parts, you’ll likely add years of breakdown-free air conditioning.

Via – DIY Air Conditioner Repair

When it comes to troubleshooting an air conditioning system you may find some of it easy to deal with and some may not. It’s always best to consult an expert but in order for you to save services cost for simple configuration and fixes, I suggest you read on further.

But first, you should know the flow of how a central air conditioning system really works. There are lots of different brands and models but most of them run in a similar overall flow.

This image below shows how air conditioning system works:


While understanding this flow, it would be easier for you to know the basic and the top most common problems which you can easilyidentifylike a pro.


PROBLEM #1 – Leakage

If your air conditioner is low on refrigerant, either it was undercharged at installation or it leaks. If it leaks, simply adding refrigerant is not a solution. A trained technician should fix any leak, test the repair, and then charge the system with the correct amount of refrigerant. Remember that the performance and efficiency of your air conditioner is greatest when the refrigerant charge exactly matches the manufacturer’s specification, and is neither undercharged nor overcharged. Refrigerant leaks can also be harmful to the environment.

PROBLEM #2 – Inadequate Filter and Coil Maintenance

If you allow filters and air conditioning coils to become dirty, the air conditioner will not work properly, and the compressor or fans are likely to fail prematurely.

PROBLEM #3 – Control Failure

The compressor and fan controls can wear out, especially when the air conditioner turns on and off frequently, as is common when a system is oversized. Because corrosion of wire and terminals is also a problem in many systems, electrical connections and contacts should be checked during a professional service call.

PROBLEM #4 –Sensor Malfunction

Room air conditioners feature a thermostat sensor, located behind the control panel, which measures the temperature of air coming into the evaporative coil. If the sensor is knocked out of position, the air conditioner could cycle constantly or behave erratically. The sensor should be near the coil but not touching it; adjust its position by carefully bending the wire that holds it in place.

PROBLEM #5 –Drainage Problems

When it’s humid outside, check the condensate drain to make sure it isn’t clogged and is draining properly. Room air conditioners may not drain properly if not mounted level.


To make it easier here’s a template of a DIY checklist you might want to go over before addressing to your ac problems to the HVAC inspector.



Problem  Possible cause  Solution 
doesn’t run
1. No power. 1. Check for blown fuses or tripped
circuit breakers at main entrance
panel or at separate entrance
panel; restore circuit.
2. Thermostat set
too high.
2. Lower thermostat setting 5°.
3. Motor faulty. 3. Call a professional.
4. Compressor
4. Call a professional.
Uneven cooling 1. Distribution
system out of
1. Balance system.
1. Thermostat set
too high.
1. Lower thermostat setting 5°.
2. Evaporator dirty. 2. Clean evaporator
3. Unit too small. 3. Replace with larger unit;
call a professional.
Unit doesn’t 1. Thermostat set 1. Lower thermostat setting 5°.
cool      too high.
2. Condenser dirty. 2. Clean condenser coil and fins;
    if necessary, straighten fins.
3. Condenser unit 3. Remove debris blocking condenser;
    blocked.     cut down weeds, grass, and vines.
4. Evaporator dirty. 4. Clean evaporator.
5. Compressor faulty. 5. Call a professional.
6. Not enough
refrigerant in system.
6. Call a professional.
Condenser unit
turns on and
off repeatedly 
1. Condenser dirty.
2. Condenser unit
1. Clean condenser coil and fins.
2. Remove debris blocking condenser;
cut down weeds, grass, and vines.
3. Evaporator dirty. 3. Clean evaporator.

Via – How to Repair Central Air Conditioners

Make a personal checklist which you can keep and do monthly or every 2 months that way you can keep track of the maintenance and parts replacement periods. It actually cost cheaper to do simple things yourself than paying contractors to do their job every now and then.

Butif you find it difficult reviewing the sections of your air conditioning system, we recommend that you contact your HVAC inspector or contractor, especially when the problem keeps recurring.

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