Air Conditioner: How To Maintain Unit and Fix Faults

Air Conditioner: How To Maintain and Fix Faults
How An Air Conditioner Works

   Before we address the usual faults found in air conditioners you should have an understanding of how an AC operates.

Contrary to what most people believe, an air conditioner is not a magical tool that creates cold air all by itself.

 The mechanism of an AC is actually pretty simple. And whether it's a window type or a split; bear it in mind that they all work the same way.

All cooling systems have five important components. They are

1. Evaporator
2. Condenser
3. Expansion Valve
4. Refrigerant
5. Compressor

They also have cooling fans, air ducts and coils for chilling warm air.

Now all your AC does is take in the warm air from your room through it's grilles. This air gets to the Evaporator which absorbs the heat by the help of a refrigerant liquid.

Because of the heat, the liquid refrigerant evaporates to become a gas (hence the name 'evaporator')...

The Evaporator also squeezes out the moisture from the air aka  dehumidifying.

Anyway, the refrigerant (now a gas) is transferred to another vital component called a Compressor.

The compressor compresses the hot refrigerant gas and sends it to the Condenser.

The Condenser  receives the refrigerant gas and condenses it back to it's original liquid form.

The condenser does this by expelling the heat the gas absorbed from the warm air. That heat is released outside the room.

I'm sure you can guess where the compressor and condenser are located. Yes they're found in that part of the machine usually placed outside the room.

In other words, that part that you can spot from outside.

So now that the gas is a cool liquid again, what next?

The liquid passes through the Expansion Valve (a small hole in the air conditioner's copper tube) and arrives back at the evaporator where it all started.

So now the heat has been sent outside and we've got cool air ready to be blown back into the room. Pretty neat, right?

This whole process is repeated until the desired temperature is achieved.

I brushed over other components like the Thermostat. It's in charge of noting the temperature difference between the room and the temperature you want.

It won't rest until you get the exact level of coldness or warmth you specified by pressing the remote.

Apart from the Thermostat, there's also the air filters for..yes, filtering particles from the air.

So now there might be instances when the AC just doesn't work like it should. It may not make the room cool enough, or worse even blow out warm air or refuse to come on.

This leads us to the next point of focus:

Common Faults In An Air Conditioner

Erratic Temperature

You might notice that the air is colder or much warmer than you specified.

This erratic temperature is possibly caused by:

Faulty Thermostat. Remember I told you that the thermostat is in charge of temperature control. So if you notice that the temperature is erratic, the thermostat is a good place to give attention.

Check to make sure it is turned on and that it is on the correct setting.

If you want a cold room, the thermostat should be set around 16 - 18°c.

Dirty Filters

Another suspect is a dirty filter. When the filters are clogged with dust, they impede free flow of air and sometimes freeze the AC unit.

Refrigerant Leaks

Remember the role of the refrigerant liquid? As stated earlier, it absorbs heat from the warm air.

So if the liquid leaks then it can also be responsible for unpredictable temperature.

Apart from erratic temperature, your AC may develop other faults:

AC won't come on

This can be caused by various factors which includes:

Bad Remote

Sometimes a bad remote can cause a lot of confusion.

So before you start running shelter-skelter, be sure your remote is functioning properly before you assume your AC is bad.

Poor connection

Be sure your power plug is properly plugged. You'd be surprised how this small issue can cause unnecessary stress.

So ensure that the wall socket or power source is well functioning.

Other suspects include blown fuses and faulty or unchecked circuit breaker.

Electric Failure

When the machine is repeatedly switched on and off, electric failure can arise.

The fan controls and thermostat can fail. Also the wires and terminals may experience wear and tear and all this can prevent the AC from starting or cause it to trip off at intervals.

Bad Capacitors

Capacitors store electric charges. And your system has a capacitor that activates the motor and a run capacitor that keeps the motor running. Needless to say, if the capacitors are bad, the AC would malfunction.

Bad Contactor

The contactor is responsible for creating the electrical connection that starts the compressor and motors.

If the contactor is worn out, the compressor won't start. So your AC won't cool temperature as expected.

One final fault I want to highlight is a leaking AC. So if you’ve ever asked 'why is my AC leaking?'

Water may leak from your unit after you turn it off. You can blame frozen coils for this. Your coils can get frozen when there is erratic temperature. 

Refer to the section where I addressed erratic temperature. Also if the drain is clogged then, the condensed moisture that should drain out will be trapped and accumulate to cause leaking.

So make sure your unit’s drain is unclogged.

Leaking is usually solved by switching off the machine for some time. 

So if after cleaning the coils and drain, you still notice leaking, try to contact a technician to address the problem.

Most of the faults your AC may develop over time revolve around the thermostat, power source which includes (plugs, cords, capacitors, contactor), evaporator coil, condenser and compressor.

Therefore in order to prolong the health of your system, you need to observe good maintenance practices. These include:

How To Maintain Your AC

Change or clean the air filters once every month.

Trust me, you don't want to skip on this if you hope to keep you AC working at it's peak.

Dirty air filters stress the system and reduce the quality of air it circulates.

Clean the Coils

The coils can usually be accessed after you have removed the filter and bezel.

You should use a spray cleaner for this purpose. But try not to spray on electrical wires and other sensitive electronic surfaces.

Cleaning the coils will save you from that moldy, damp smell associated with dirty air cons.

Inspect the fins

Your compressor and condenser have fins. Kind of like the fins if a submarine. These fins drive the air round the system as I earlier explained. If the fins are bent then you should get a fin comb or call an expert.

So that's basically what you need to know about your cooling unit and it faults and maintenance tips. Please leave a comment if you have any questions or problem concerning air conditioners.