5+ Most Common Summer A/C Problems

August 09, 2018

So, your A/C has survived so far...  

It’s been a seemingly endless Summer.  Temperatures approached the 90’s early and have stuck around for months.  Hopefully, your A/C has been up to the task and your home has stayed comfortable throughout.  But based on our experience, different parts of the season tend to bring more consistent breakdowns and repairs.  (Many of which are preventable!) Below are some of the most frequent issues that can be resolved before they have you sweating.

Here are 5+ things that most frequently break down in the dog days of Summer:

1. Capacitors
One of the most common breakdowns of current air conditioning systems is failure of the run capacitor.  A run capacitor is a device which helps the motors on startup and throughout their run cycle.  When they fail, typically the fan motor or compressor will struggle to start and inevitably shut off via an internal safety mechanism.  Older style capacitors had a type of coolant known as PCB oil which was well regarded for its longevity.  But, since the discovery of PCB to be a carcinogen and environmentally toxic, its use has been banned.  Newer capacitors use castor oil but don’t typically last as long.  Unfortunately, it’s when temps are at their highest that your capacitor is most likely to fail.  Many times the capacitor can fail without warning but it is possible to diagnose a weak capacitor before an inevitable breakdown.  

2. Low on refrigerant (again)
Early in the cooling season, it’s not uncommon to find your A/C is low on refrigerant.  The A/C circuit should be a sealed system which means you should never HAVE to add to it.  Though it's not uncommon to have a small leak which requires a recharge of your A/C.  But if your leak is big enough, it can require multiple recharges throughout the year.  This can become very expensive with the consistent rise in price of freon and the progressive inefficiency of your A/C as the leak continues.  And remember, leaks will only get larger over time if left unrepaired.  We recommend getting a leak check done anytime your system is low so you may have repair vs. replace options.

3. Dirty filters
    The more your HVAC system runs, the more quickly your air filter will get dirty.  So during peak season you can expect to replace your air filter more often.  Most one-inch thick filters are designed for replacement every 3 months, but this can vary greatly from home to home.  Pets, kids, traffic in and out of the house, and even hardwood floors can contribute to a dirty filter.  Paired with prolonged 90+ degree temperatures and you may need to replace your filter within weeks, not months.  Our recommendation is to invest in a “middle-of-the-road” pleated air filter which will help capture most of your household dirt without being overly restrictive on the system.  If you prefer higher efficiency air filters, for example to help minimize allergies, plan to change them a little more often.  A dirty air filter is one of the biggest enemies of efficiency in your HVAC system, but is also one of the easiest aspects to maintain.

4. Dirty A/C coils
    Just as your air filter gets dirty when your system runs frequently, so does the A/C unit itself.  Did you know your A/C can process more than 100,000 pounds of air per day?!  Imagine the amount of dirt and debris that is carried in that air! Lawn clippings, pollen, and dust will accumulate on the A/C and progressively reduce the efficiency of your system, driving up your utility bill.  If it’s neglected long enough it can actually cause your system to overheat and breakdown.  The simple solution is taking a mild pressure hose to wash off the outside coils.  Some units are more difficult to clean than others as it may require taking panels off to adequately clean.  Best practice is to have the unit cleaned during routine maintenance at the beginning of the season, but also throughout the summer depending how often your A/C is running.

5. Clogged drains 
    As your A/C cools the air -- it is also actively dehumidifying.  All that water being removed from the air runs through a small drain hose that can accumulate to gallons per day of water runoff.  Along with that water is any dirt that has made it past your air filter, as no filter is 100% efficient at catching dirt.  So the more your A/C runs, the more dirt and sludge is created which can clog your drain.  Blowing out the drain line is an easy way to ensure water is going down your drain and not into the furnace cabinet where damage can be done.  If you ever see water accumulating in or under the indoor equipment, call a trusted professional for service ASAP.

6. Motor failures
    Motor failures are unfortunately one of the more expensive repairs on an HVAC system.  Their cause may be any one of the items listed above.  A failed capacitor can cause excess strain on a motor as it tries to start repeatedly before overheating and eventually shutting off.  Dirty equipment creates additional stress on a motor to do its job.  Lack of freon creates longer run times and overuse while simultaneously damaging the compressor.  Keeping your equipment clean and maintained is the best way to extend the life of your equipment to survive the long, inevitably hot St. Louis summer!