Why Is AC Not Cooling?

Few things test your patience like an air conditioner that runs all afternoon while the house keeps getting warmer. In the Yakima Valley and Tri-Cities that usually happens on exactly the hottest day of the week. The good news is that a short list of causes explains most of these calls, and a couple of them are things you can check without tools.

Check the easy things first

• Dirty air filter: clogged filters restrict airflow and cut cooling capacity, and replacing one costs very little
• Thermostat settings: make sure it is on, set to cool, set to a temperature below the room temperature and has fresh batteries if it uses them
• Vents and registers: confirm they are open and not blocked by furniture or rugs
• Outdoor unit: look for leaves, cottonwood fluff, grass clippings or debris against the coil and clear it away gently

A dirty filter is one of the most common reasons for weak cooling and also one of the easiest to fix. If you have pets, a dusty house or recent construction, check it monthly during summer. If the thermostat is blank or unresponsive after a battery change, the problem may be wiring or the thermostat itself, and that is worth a service call.

It also helps to know what normal looks like. An air conditioner cools the air that passes through it by a noticeable margin, so air from the supply vents should feel clearly cooler than the air at the return grille. If the difference is small, or if the system runs for hours without reaching the set temperature, that is useful information to give the technician when you call.

Dirty coils and low refrigerant

Your air conditioner moves heat from inside the house to the outdoor coil, which releases it to the air. When that coil is caked with dirt, the heat has nowhere to go. The system runs longer, cools less and works under added stress. Cleaning the coils is a standard part of seasonal maintenance, and skipping it for several years is a common reason for poor performance.

If the air from the vents is warm, there is ice on the refrigerant lines, or you hear a hissing sound near the unit, refrigerant may be low or leaking. Refrigerant does not get used up like fuel, so low levels mean there is a leak somewhere. That needs a technician with the right equipment to find the leak, repair it and recharge the system properly. Topping off without repairing the leak only delays the next failure.

If you see ice, turn the system off and let it thaw before you call. Running a frozen coil can damage the compressor.

Blocked or leaky ducts

Even a healthy air conditioner cannot cool a house if the cool air never gets there. Ducts can be crushed, disconnected, chewed by pests or worn out with age, especially in attics and crawlspaces where Yakima Valley summer heat is brutal. Symptoms include rooms that never cool, weak airflow from some vents and cooling bills that seem too high. If you cannot find the problem by looking at the vents and registers, a duct inspection will.

An aging system, and when to call for help

Motors, blowers, capacitors and other parts wear out over time. If your air conditioner is over 10 to 15 years old and the repair costs nearly as much as replacement, it may be time to talk about an upgrade. Replacing in spring or early summer, before the heat peaks, is easier than doing it during a heat wave.

If the basic checks do not bring the cooling back, stop running the system hard and call. Continuing to run a system with a refrigerant leak, a failing motor or a frozen coil can turn a small repair into a big one, and it will push up your energy bill in the meantime.

ACT Heat & Air services all air conditioner makes and models, including split systems, packaged units, heat pumps, ductless systems, VRF and rooftop units, and we offer 24 hour emergency service. Call (509) 388-2997 for an inspection in Yakima, Union Gap, Ellensburg, Prosser, Kennewick, Richland or Pasco.