When your AC starts leaking water inside your home, you don’t have time to scroll through vague advice.
Whether it’s a slow drip or a sudden puddle, an AC leak can cause major damage fast, especially during a hot and humid Chicago summer.
Our team at ServiceMaster of Lake Shore has helped hundreds of Chicago homeowners clean up and fix AC leaks in condos, single-family homes, and high-rises.
Here’s a guide on what to do if you’re experiencing this issue.
Key Takeaways
- If your AC is leaking, start by checking the drain pan, clearing out the drain line, and replacing any dirty air filters. If you think it’s a refrigerant leak, you’ll need a pro to handle it safely.
- Don’t ignore signs like water leaking inside, weak cooling, longer run times, higher electric bills, strange hissing sounds, or extra humidity in your home.
- If the leak has caused water damage, call a professional restoration team like ServiceMaster of Lake Shore at 312-707-8597.
Signs Your AC Might Be Leaking Water Inside
You might not notice the leak right away. These are red flags we commonly see in Chicago homes:
- Water pooling near the indoor AC unit
- Warm air coming from vents, even when the AC is running
- Longer cooling cycles and rising electric bills
- Musty smells or visible mold around floorboards or vents
- Hissing or bubbling sounds near the air handler
- Indoor humidity levels that feel sticky and uncomfortable
How to Fix an AC Leak in Your House (Step-by-Step)
Before you start, turn off your AC and have the following ready:
- A flashlight
- Towels and a bucket
- Shop vac (if available)
- White vinegar
- Wire brush or pipe cleaner
- Replacement air filter (check size first)
Step 1: Check and Clean the Drain Pan
- Turn off your AC system.
- Open the access panel and locate the drain pan under the evaporator coil.
- If there’s standing water in the pan, vacuum it out and give it a good scrub with soap and water.
- Then pour in a cup of clean water to check for cracks.
- If water leaks through, seal the cracks with waterproof epoxy, or replace the pan if it’s too damaged.
Chicago Tip: If you live in an older brick building or high-rise, especially one with the AC unit tucked in an attic or closet, your drain pan is more likely to rust out quickly. Check it regularly for cracks or corrosion to avoid hidden leaks and water damage.
Step 2: Clear the Drain Line
- Look for the plastic or copper pipe near your indoor AC unit.
- Use a wire brush to gently clean out any gunk or buildup inside.
- Attach a shop vac to the outdoor end and run it for a few minutes.
- Pour 1 cup of white vinegar into the indoor opening.
- Watch the outdoor end: if nothing drains, you may need professional help.
Step 3: Replace the Air Filter
- Dirty filters block airflow, causing coils to freeze and leak.
- Locate your return vent and pull out the filter.
- If it looks gray, dusty, or soggy, replace it immediately.
- Write the date on the new filter to help track replacement timing.
Step 4: Inspect the Evaporator Coil for Ice
- Shine a flashlight on the coil above the drain pan.
- If you see frost or ice, it may indicate a refrigerant leak.
- Turn off the unit and call an HVAC technician—this step requires professional tools and certification.
Warning: Refrigerant leaks (like R-410A or older Freon systems) are dangerous and should never be handled without a license.
What to Do About Water Damage from an AC Leak
Even after you stop the leak, water damage can keep spreading. Here’s what we advise:
- Soak up standing water with towels or a wet vac.
- Set up fans and open windows to speed up drying.
- Check baseboards, walls, and flooring for hidden moisture.
- Call our Chicago water damage team for a full inspection.
- Document everything with photos for your insurance company.
Case Study: AC Leak Cleanup in a Lakeview Condo
In a Lakeview condo, an AC leak from the upstairs unit caused Category 2, Class 2 water damage in multiple areas of the home.
Our team removed sections of ceiling and drywall to access trapped moisture, then cleaned and sanitized all affected surfaces.
We set up air movers, dehumidifiers, and air scrubbers to dry the space and improve air quality.
With fast response and professional equipment, we prevented further damage and restored the property with minimal disruption.
Need Help After an AC Leak in Chicago?
Even if you’ve fixed the AC, the water damage might linger in floors, walls, or nearby rooms. Don’t wait until it turns into mold.
We serve all Chicago neighborhoods and suburbs, including River North, West Loop, Gold Coast, Lakeview, and Evanston.
Call ServiceMaster of Lake Shore at (312) 707-8597 or request an inspection online.
FAQs
What Causes AC Leaks in Chicago Homes?
Based on the jobs we’ve responded to, here are the most common culprits:
- Clogged condensate lines (mold/algae buildup)
- Cracked or rusted drain pans
- Frozen evaporator coils (from dirty filters or low refrigerant)
- Refrigerant leaks due to wear and tear
- Improper installation or system aging (common in vintage or flipped properties)
How do I know if my AC leak is serious?
If it happens more than once, leaves standing water, or shows signs of mold, call a pro.
Can I fix a refrigerant leak myself?
No. Refrigerant handling requires EPA certification and professional tools.
What’s the fastest way to prevent another leak?
Change your filter every 1–2 months and pour vinegar in the condensate line monthly during summer.
