A modern air conditioner system is complex; there are electronic, electrical and moving mechanical parts that must work together in harmony. But, when an issue arises, there are a number of common problems that can be identified easily. If you experience these problems, it’s time to contact your local heating and cooling specialist for expert help. Why? Well an AC system represents a significant investment and it makes good sense to protect it from further damage. A DIY ethos is admirable, but working on these systems without adequate skills and experience can make the problem much worse. In this article, we will look at five common AC problems in more detail.

1.  The AC System Will Not Blow Cold Air

If you turn on the AC system and it’s not blowing any cold air, the problem may not be as serious as you might imagine. Before you call a HVAC technician, check that the thermostat is set to the correct temperature and the vents are open. This may seem obvious, but during the transition from one season to the next, many people forget these two simple things. Another common cause is a clogged air filter which inhibits the airflow making the air feel warmer than it should. In extreme cases, this lack of airflow can cause freezing within the evaporator coils which will exacerbate the problem. Another possible cause is a loss of refrigerant which degrades the efficiency of the entire AC system.

The Solutions:

Set the proper temperature, open the vents, change or clean the air filter and wash the evaporator coils with mild soap, clean water and a soft brush. If the blower motor is not delivering the treated air, contact a local heating and cooling specialist to replace it.

2.  The AC System Cannot Deliver Sufficient Cool Air

Again, check all the vents in the home, they all should be open as even one closed vent can degrade the cooling performance. Many people try to “save money” by cutting off the cooled air supply in rooms that are not used regularly. This is a false economy and the system works more efficiently if every room is cooled evenly. If there is a refrigerant line leak or if the system is too old or improperly installed, there may be airflow problems.

Another big problem is an air conditioning system that has been improperly sized to match the size of the home. Some people simply purchase the largest system that they can afford and install it in their homes because bigger must be better. This is a flawed approach. If the system is too large it will cool the space quickly and then shut down prematurely which is known as short cycling. This damages the heating and cooling equipment with no gain in performance. If the system is too small, it will run constantly because it cannot cool the space and this drives up the energy bills.

The Solution:

As you can see, the AC system must be correctly sized to deliver the performance and energy efficiency that you need. A load calculation is required to find the right system size and this requires a number of carefully measured variables including the home orientation, the number of windows, the insulation levels and many more. For this reason, it’s advisable to contact your local heating and cooling specialist to carry out the load calculation.

3.  The AC System Will Not Turn Off

If the AC system will not stop running or it stays on longer than it should, the problem is probably a dirty air filter. Another possible cause is short cycling caused by improper sizing when the system was initially installed. If the thermostat is damaged or the cable that connects it to the system has shorted, this can make the system run constantly. The final cause is a stuck fan relay that makes the fan cycle constantly even if the system is not running.

The Solutions:

The first and easiest thing to check is the air filter. If it’s dirty, it should be cleaned or replaced and if you can’t remember when you did this go ahead and do it now. Improper sizing is harder to fix without professional intervention and that goes for the other potential causes shown above. Contact your local HVAC specialist and ask them to investigate and fix the problem for you.

4.  The AC Unit Will Not Turn On

If you have a central AC system that will not turn on, the problem could lie in the thermostat if it’s not turned on or set to the correct temperature. If you have a window AC unit that won’t start, check the temperature setting and make sure that the unit is receiving power.

The Solutions:

Remember that the thermostat is the brain of the entire HVAC system. If you have a problem, it’s always a good idea to check the thermostat first and the fix may be simpler than you might expect. If the systems are set to the desired temperature and they are receiving power it’s time to contact your local HVAC technician. They can identify the cause of the problem and carry out a repair or replacement for you.

5.  The AC Blower Fan is Not Working

If the air conditioner seems to be working properly, but you cannot feel any cool air at the vents, the problem may be a malfunctioning blower fan unit. This component blows the treated air throughout the home and if it’s not working the home will feel warmer.

The Solutions:

Check the breaker for the AC system to ensure that it’s not been tripped. If everything looks fine, it’s time to check the air filter to ensure that it’s clean and not inhibiting the air flow. There may be ice on the evaporator coil and/or refrigerant lines that needs to melt to get the system working efficiently. Fixing or replacing a blower unit is a job for a trained and experienced HVAC specialist.

If you’re experiencing these or other AC system problems, contact your local heating and cooling technician.