Like many of the hvac training topics that are covered here in this blog, this one will be dedicated to central air conditioning. I will make more posts on hvac training that are referring to cars and window units but for this particular post I will go over the most basic and most common hvac problems that I encounter day in and day out as an hvac technician working on central air conditioning systems, so let me go over some basic air conditioner troubleshooting tips that may be of some use to you.
The most common complaint that I get from customers is that their a/c not cooling. Now this could be many different reasons for this, and this is the whole point of the post as I am going over the common problems that prevent the a/c from cooling, and most of them you can take care of yourself even if you have had no hvac training at all.
Dirty A/C Filter – First thing that I do when I get a air conditioner not cooling call is that I check the air filter, or furnace filter whatever you want to call it. I do this before anything. If you live in a humid spot that requires you to run your air conditioner all of the time then you need to keep up on your air filter, they should be changed once a month depending on what type of air filter it is that you are using. A dirty air filter will cause your central air conditioning system to not function as effective as it should, that is the basics of hvac training. Think about it the way that hvac works is that the warm air is removed from the room that is trying to be cooled and it is escorted outside. A dirty air filter will cause a restriction in air flow trying to get out of the house, which will make the cooling process a lot harder and a lot less efficient, so check your air filter monthly at least. There are many people out there with no hvac training that have no clue about this, and most of these people have lived in apartments all of their life and they do not know better, if you are one of these people that did not know do not feel bad it happens all of the time. That is what I am here for to give you the proper hvac training for the beginner, so with that being said let me go on to the next most common problem that I run into with central air conditioners not cooling.
A/C Coils Dirty – Now there are two sets of coils that are on a central air conditioning system, one set of the coils will be inside and the other is on the condenser itself which is located outside. So for the second hvac training tip is that you want to keep both sets of coils clean, for if they get dirty they will cause a restriction of air flow. For the inside air conditioning cools you want to make sure that you are always keeping your air filter clean, as explained in the above statement. If you do not have an air filter in at all that means that there is nothing to catch the dirt, dust, and all the other stuff that will clog up your inside air conditioning coils and prevent your system from cooling efficiently. Your inside air conditioning coils should be bright and shiny, free of debris, if they are not and they are dirty, there are many types of coil cleaners that are out there that will do a good job. I will cover coil cleaning in future posts as this is a whole other type of hvac maintenance and will require some basic hvac training before you attempt to do this. For the outside coils it is a little different, since there is no filter on the outside condenser. But the outside condenser is constantly blowing out air and there is no suction, and outside coils compared to the inside ones rarely get clogged up. Just make sure that wherever your condenser is located to make sure that it is not smothered by anything that would restrict the air being released, such as bushes and plants surrounding the condenser, leaves, shrubbery etc.
No Power – Another hvac training tip is if the air conditioning unit is not turning on at all, it is missing power somewhere. Most central air conditioners have two types of power that make the unit run, this is 240 volt and 24 volt. The 24 volt line tells the unit to kick on, while the 240 is the main power behind it all, without both working properly the central air conditioning unit will not work at all. The first thing that I do when I run into this problem is I check the breaker for the unit. If it is tripped then I simply reset the breaker by turning it off all the way and pushing it back to the on position. Then I will wait a couple of minutes to see if it trips again, if it does then there is a loose wire somewhere in the system, a bad breaker, or further electrical troubleshooting that I will get into in detail later. If the unit is running fine after the breaker is reset then the problem is usually fixed, unless it keeps tripping, which could be a amp overload and it might require a bigger breaker, you will need an amp meter though to determine this for sure though.
Another reason that there may be no power to the central air conditioning unit is that the float switch inside the air handler might be tripped. The float switch is located inside of the air handler in most cases and is usually positioned close to the coils, since there must be a pipe running from the drip pan. What happens is that over time your condensate line will get clogged up with sludge slime eventually if you do not do routine maintenance on your hvac condensate drain system, this will cause water to eventually build up, or condensate. When the drain line is clogged up with slime sludge the condensate will have no place to go and this will cause it to back up and flood your home, unless you have a float switch installed which you should, its regulation in most states. The water will push up on the float switch, thus cutting the power to the 24 volt brain of the hvac system, which will cause the a/c to lose all power. The way to cure this is to clean out the drain line, there are many ways to do this, but the best way that I know of is a wet dry vacuum.
These are just some of the most common problems that I run into when trouble shooting an hvac system here in the sunshine state Florida. There are many more possible reasons that the air conditioning system may not be working, like the unit could be low on Freon, electrical issue (could be so many), bad contactor, bad relay, bad blower fan, blown fuse, the list goes on and on and I will cover all of these I promise. But if you came here for some hvac training for the beginner, then you need to take all of this in slowly and learn the basic principles. I do not want to overwhelm you with too much information at once but if you need immediate assistance please just leave a comment and I will get to you as soon as possible, that is today’s lesson in hvac training I hope you all enjoyed it and learned something.