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Premier Heating & Air Blog

Why Your AC Is Running for So Long


When your air conditioning system won’t turn on, you know it needs help, probably from professionals who offer HVAC repair in Covington, GA like us. You may not have considered that the opposite problem can occur—an AC that won’t shut off or which runs in cycles much longer than 15 minutes—but it does happen. If it’s happening in your house right now, you’ll want to know what’s going on and to do about it.

An AC that’s running for much longer than it should is a problem all on its own, since it will waste energy and make your house too cold. What could cause this? We’ll look into the possibilities below.

An electrical malfunction

The majority of repair issues with air conditioners are related to electrical problems. In the case of a non-stop AC, there may be a fault with the control board or with a stuck motor relay that’s causing the electricity to continue to flow to the motors when it should’ve been cut off. Any electrical work on an AC must be left to professionals.

A faulty thermostat

The thermostat may be sending incorrect signals to the AC, causing it to run for longer than necessary. The simplest explanation is that the thermostat is miscalibrated so it’s reading the indoor temperature as hotter than it actually is so that it keeps the compressor running for too long. The thermostat may have lost the specific connection it has to the air conditioner that signals it to shut off either the compressor or the blower fan. Technicians can recalibrate the thermostat or repair/replace it to fix this problem.

Leaks in the ducts

The air conditioner may be working just fine, but the ductwork has air leaks allowing too much cool air to escape before reaching the rooms. This loss of cooling is something the air conditioner will need to make up, resulting in it running longer than it should. Professionals can locate duct leaks and seal them up.

Clogged air filter

An excessively dirty air filter that’s been left in place long after it should’ve been replaced can create many different problems for an air conditioner, including running nonstop. Make sure to have the filter changed for a clean one every one to three months.

The AC is undersized

If this is a new air conditioning system for your home, then a likely cause of these long cooling cycles is that whoever installed the system picked a unit that’s too small. An undersized AC will not be able to reach the target temperature on the thermostat, leading to excessive runtimes. The only way to fix this is to have the unit replaced—and to make sure that professionals who understand sizing do the job.

The AC is dying

If you have an air conditioner that’s more than 15 years old, a malfunction like non-stop cycles is usually a big indication that the system is too old to keep around. In this case, the air conditioner may have lost enough cooling capacity that it must overwork in order to keep the house cool. The best way forward at this point is to get a brand-new system.

Experience the Premier Difference! Premier Heating & Air has been family-owned and operated since 2001.

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