After the Storm: How to Check Your AC for Damage

This month's storms left plenty of West Michigan yards looking rough. Limbs down, shingles in the grass, trampolines in the wrong yard. That's what Lake Michigan weather does in July: the lake feeds those lines of thunderstorms, and by the time they cross Jenison and Hudsonville they've got wind, hail, and enough rain to pond water in low spots.

Your air conditioner sat outside for all of it. Most units come through a storm just fine, but "most" isn't "all," and the ones that got hurt don't always look hurt from the kitchen window. The expensive failures I see after a storm usually started with someone flipping the system back on without looking at it first.

So before you fire it up, give it ten minutes. Here's the walk-around I'd do at my own house, outside first, then inside.

Before You Touch Anything: Kill the Power

Next to the outdoor unit, mounted on the wall of the house, there's a small gray or metal box. That's the disconnect. Pull the handle or flip it off before you put your hands anywhere near the unit. Storm-damaged equipment can have loose wiring, and a condenser can kick on by itself the moment the thermostat calls for cooling. I don't inspect a live unit and neither should you.

One more thing while we're on electricity. If there's a downed power line anywhere near your house or yard, stop. Don't go near it, don't move branches around it, don't assume it's dead. Stay away and call Consumers Energy, and check their outage map at consumersenergy.com. No AC checklist is worth going near a live line.

Step One: Look at the Fins for Hail Damage

Walk around all four sides of the condenser and look at the thin metal fins, the ones that look like the edge of a radiator. Hail dents them. The question is how badly.

Light, scattered denting is mostly cosmetic. A few dings here and there won't change how the system runs, and I wouldn't lose sleep over them. What matters is airflow. When hail flattens whole patches of fins, air can't pass through the coil, and the unit has to work harder to shed heat. That shows up as longer run times, higher bills, and eventually a compressor running hot enough to shorten its life.

There's a tool called a fin comb that straightens bent fins, and for mild damage it works fine. But if the fins are crushed flat across large sections, or the coil tubing behind them looks dented, that's past the fin-comb stage. Bent coil damage is a pro call, because straightening fins over a damaged coil can open a refrigerant leak you didn't have before.

Step Two: Clear the Branches and Debris

This one's simple but it matters. Pull branches, leaves, shingle pieces, and whatever else the storm delivered off the top of the unit and away from the sides. Look down through the top grille too, because twigs and maple seeds love to drop through the fan guard and sit on the coil or against the fan blades. A stick resting where the fan spins will announce itself loudly the moment you restart.

While you're at it, restore the two feet of clear space the unit needs on all sides to breathe. Storms have a way of relocating half a bush onto the condenser. I walked through the whole cleaning routine in how to clean your AC condenser, and a post-storm rinse of the coil isn't a bad idea once you've confirmed there's no real damage.

Step Three: Did It Take a Real Hit?

A direct hit from a falling limb is a different story than some scattered twigs. If something heavy landed on the unit, check three things.

First, the cabinet. Is the top caved in or the fan guard bent down toward the blades? A fan blade striking a bent guard will destroy the motor in short order.

Second, the pad. The condenser should be sitting flat and level on its concrete or composite pad. If the impact shoved it sideways or tipped it, don't run it. A unit that shifted even a few inches can stress everything connected to it.

Third, and most important, the copper lines running from the unit into the house. That's the line set, and it carries the refrigerant. Copper bends easily and doesn't bend back. A kinked line restricts flow; a cracked joint leaks. Signs of a refrigerant leak include a hissing sound near the lines, oily residue at the connections, or ice forming on the lines once the system runs. Any of those means leave it off and schedule AC repair.

I looked at a unit in Grandville last week where a maple limb had come straight down across the line set. The condenser itself looked untouched. The copper behind it was creased almost flat. If the homeowner had just cleared the branch and hit the thermostat, the compressor would've been starving for refrigerant within the hour.

Step Four: Water

Heavy rain around the base of the condenser is normal and drains off. These units live outside; rain is part of the job description.

Standing water is worth a closer look. If your unit sits in a low spot and there's still ponded water around it a day later, the pad may be settling or the grading needs work, and prolonged soaking isn't good for the base of the cabinet.

Submersion is the serious one. If floodwater came up more than a few inches on the unit, and you can usually see the mud line, do not just fire it back up. Water that deep reaches the electrical controls, the contactor, the capacitor, and the wiring connections, and floodwater carries silt that gets into everything. Motors and controls that got soaked can fail immediately or fail weeks later. Leave the disconnect off and have the unit inspected before it runs again. Sometimes it's a cleanup and a few components. Sometimes it's not. But guessing wrong costs a lot more than the inspection.

Now Check Inside

Outside looks good, power's back on at the disconnect, and you've started the system. You're not quite done. Give it fifteen minutes and check three things indoors.

Airflow at the vents. Cool, steady air at roughly the strength you're used to. Weak or warm airflow after a storm can point to a coil problem outside or a system that lost its charge.

New noises. You know your system's normal soundtrack. Rattling can be storm debris in the cabinet, buzzing can be an electrical component that took a hit, and grinding means shut it down. I covered the whole vocabulary in what strange HVAC noises mean.

The breaker. Storms and the power blinks that come with them are hard on AC electrical parts. If the breaker trips once, reset it once. If it trips again, stop. Repeated trips mean a real fault, and I explained why in why your AC keeps tripping the breaker. And if the system simply won't wake up now that the power's back, run through what to check when your AC won't start after an outage before you assume the worst.

The Insurance Side, Briefly

I'm not an insurance agent, but I've been part of enough claims to know the pattern. Hail, wind, and falling-tree damage to an AC unit are commonly covered under a standard homeowners policy, subject to your deductible. Flood damage is its own category and depends on your coverage.

Two things help a claim. Photos of the damage before cleanup, which you've already got if you followed the tip above. And a written assessment from a licensed contractor stating what was damaged, what caused it, and what repair or replacement will take. Adjusters take a documented professional opinion seriously. We put those together on service calls all the time, so if you're filing a claim, say so when you schedule and we'll write it up while we're there.

What I won't do is inflate an assessment to pad a claim, and you should walk away from any contractor who offers to. That kind of thing follows the homeowner around, not the contractor.

When It's More Than a Checklist

If any point in this walk-around turned up a burning smell, sparking, a hissing refrigerant line, or a unit that's clearly wrecked during a hot stretch, that's beyond a to-do list. Head to our emergency page or just call. And if it's simply "something's not right and I'd rather not guess," that's a perfectly good reason to have us out too. Ten minutes of looking is what I'm asking you to do; I'm not asking you to diagnose a compressor.