The noise started after Thursday's thunderstorm: Lake City air conditioner sounds that arrive overnight, and the ones that creep up over a summer

Two kinds of new noise

Every air conditioner in Lake City makes a sound, and a homeowner knows their own. What brings the phone call is a sound that was not there before, and the single most useful question we can ask is: when did it start?

If the answer is a date, usually the evening after one of the afternoon storms that roll across Columbia County from June through September, or a morning after a windy night under the pines, the noise is probably damage. If the answer is “I’m not sure, it has been getting worse,” the noise is probably wear. Those two groups have different causes, different urgency and different fixes, and sorting your noise into one of them is most of the diagnosis.

Sudden sounds: lightning, limbs, and a fan that took a hit

Lake City sits under summer lightning more days than not, and two storms in two years, Idalia in 2023 and Helene in 2024, dropped trees and limbs on outdoor units across the county and knocked out power for days. Sudden noises after weather tend to be these:

• A loud electrical buzz from the condenser with nothing turning. A capacitor or contactor that failed under a surge, or a compressor trying to start against a locked rotor. Shut it off.
• A rhythmic ticking or scraping from the outdoor fan. A blade bent by debris, or a pine limb or cone lodged in the grille striking the fan each turn. Often visible from the yard.
• A new rattle from the cabinet. Panels loosened or a unit shifted on its pad by wind or a falling branch.
• A chattering at the air handler. A control board or relay damaged by a surge, cycling things it should not.
• Silence where there used to be sound, then a clunk on restart. Power came back after an outage with a surge, and the system is not starting cleanly.

Any of these after a storm deserves a look before the next one, because a bent blade that still runs is a motor failure waiting for a hot afternoon.

Slow sounds: bearings, belts and pollen-packed coils

Wear noises build over weeks or a season, and in this town the season that builds them is spring. Pine pollen in March and oak catkins in April pack the outdoor coil and work into the indoor blower wheel; by July the wheel is out of balance and the motor bearing is complaining. The slow noises:

• A grinding or rumbling from the air handler that rises in pitch over weeks. Blower motor bearings. Fixable while it is a noise; a seized motor is a warm house.
• A screech or squeal at startup that fades. A belt on an older unit, or a bearing that is dry. On a system from the 1980s block ranches it can be a belt-driven blower still in service.
• A deepening hum from the condenser and longer run times. A coil so matted the fan is working against it; the noise and the bill rise together.
• A gurgle or hiss at the indoor coil. Refrigerant at a low charge, which often means a slow leak at a coil past its twelfth year.
• A whistle at the return grille or filter slot. A filter too restrictive for the grille, or a return that has always been too small and now has a caked filter in it.

Have the noise identified

Which sounds mean turn it off at the breaker

Most noises can wait for a scheduled visit. A few should not run another minute. Turn the system off at the thermostat, and if it keeps making the sound, at the breaker, when you hear: a loud, continuous electrical buzz from the condenser with nothing moving; metal-on-metal grinding from either unit; a repeated hard clunk from the compressor at each start; or any sound paired with a burning smell, a tripped breaker that resets and trips again, or ice on the lines. Then call 866-266-5709. There is no after-hours charge for the call or the visit, so there is no reason to let a grinding compressor run through the night.

What a noise visit looks like from the driveway

We ask you to leave the system in whatever state makes the noise, unless it is on the shut-it-off list, because a noise we can hear is a noise we can find. The technician listens at the condenser, then at the air handler, then in the attic if the sound is in the duct. Panels come off; the fan is spun by hand; the blower wheel and bearings are checked; the capacitor and contactor are tested under load; the refrigerant charge is read if there is a hiss or gurgle. Storm damage gets photographed in case there is an insurance claim behind it. Most noise calls in Lake City end with a part from the truck and a quieter driveway. A few end with a conversation about a motor or a compressor on a system old enough that the repair price and the replacement price belong on the same sheet, and we put them there.