Water Leaking from your AC? Clogged Condensate Drain Fixes for Coastal SC
Water pooling under your indoor AC unit almost always traces back to a clogged condensate drain. Here is what to check in the first fifteen minutes, the less common causes that need a technician, and how Comfort Masters diagnoses and fixes a leak across North Myrtle Beach and the Grand Strand.
AC pooling water? Shut it off now. A clogged condensate drain line is the most common cause on the Grand Strand, where Comfort Masters Heating & Cooling’s air conditioning repair technicians see it show up hardest during peak cooling season. This guide covers what causes it, what to check safely, and when it needs a professional.
Quick answer
What to do in the next 15 minutes
Turn it off now. Water pooling under your indoor AC unit is most often a clogged condensate drain line, especially during peak cooling season when the coil stays wet most of the day. If you can safely reach the outdoor end of the drain line, clear it with a wet or dry shop vac. Call a technician if the leak continues, or if water is near an outlet or electrical panel.
Quick checks before you call
A few checks take five minutes. They can save a wasted trip. Confirm the thermostat is set to cool and the system is actually running. Look at the air filter, since a filter clogged with dust or pet hair can freeze the coil and cause a delayed leak once it thaws. Check the drain pan under the indoor unit for a hairline crack, because a cracked pan leaks even with a clear drain line.
What’s causing your AC to leak water
Most common causes
A clogged condensate drain line causes most leaks. Algae, dust, and coil residue build up inside the PVC line over a cooling season and slow the flow until water backs up into the drain pan and overflows. A clogged condensate drain line is the single most common reason a Grand Strand air conditioner leaks water. Energy Star’s official maintenance checklist lists checking and inspecting the condensate drain as a required part of an annual professional tune-up, precisely because this line clogs on a predictable schedule. The U.S. Department of Energy’s home cooling guide recommends periodically passing a stiff wire through the drain channel to prevent exactly this kind of buildup. A dirty air filter is the second most common cause, since restricted airflow across the coil leads to icing that overflows the pan once it thaws, an issue covered in more depth in a frozen coil thawing out too fast.
Less common but serious causes
A cracked or rusted drain pan leaks even when the line runs clear. That means the pan needs replacing, not just clearing. A disconnected or crushed drain line in an attic or crawlspace can send water into ceiling drywall instead of outside, which is a bigger repair than a surface clog. A failed condensate pump, common on systems installed where the drain cannot reach an exit point by gravity, stops moving water entirely once the pump motor or float switch fails.
What we do at Comfort Masters for a leaking AC
What the visit looks like
A technician traces the leak from start to finish. That means checking the drain pan, the line itself, and the coil for ice or damage. We document the cause of a leak in writing before recommending any repair. That documented diagnosis tells you exactly what failed and why, instead of a guess at what might be wrong. A service call is 55 dollars in Little River and Calabash and 95 dollars in the other service areas, and it covers the technician’s time to find the problem and put the findings in writing.
What we can address same-day
Many fixes happen same-day. Clearing a blocked drain line, resetting a tripped condensate pump float switch, and sealing a small crack in an accessible drain pan are typically same-visit repairs. A cracked coil, a crushed line buried in a wall, or a pan that needs full replacement may require a return trip once parts are confirmed. Staying ahead of the next clog is easier than clearing one, and how often to service your HVAC system covers the maintenance cadence that catches a slow drain before it backs up.
24-48h
Wet materials generally need to dry within 24 to 48 hours to avoid mold growth.
A leak that lingers under an indoor unit is a moisture and mold risk on its own timeline, separate from the HVAC fix itself.
Source: EPA, A Brief Guide to Mold, Moisture and Your Home.
When this is more than a DIY fix
Signs you need a technician now
Some signs mean stop troubleshooting. Call a technician if the leak returns within a day of clearing it yourself, if you see water stains spreading on a ceiling below the unit, or if the drain pan itself looks cracked rather than just full. A musty smell is another signal worth acting on, and a musty smell from your vents often points to the same standing moisture behind a leak.
Water near power: safety comes first
If standing water reaches an outlet, a light fixture, or an electrical panel, do not touch it. Shut off power at the breaker if you can do so without stepping in the water. Call 911 first if you see sparking or smoke.
Common questions
An AC leaking water, answered.
Why is water leaking from my air conditioner?
Most leaks come from a clogged condensate drain line. The line carries moisture the coil pulls from the air, and algae, dust, or debris can block it and back the water up into the house. A frozen evaporator coil that thaws too fast is the next most common cause.
Is it safe to keep running my AC while it is leaking?
No. Turn the system off at the thermostat first. Running a unit with a blocked drain lets water keep collecting in the pan until it overflows, which can warp flooring and stain a ceiling below the unit. Shutting the system down stops the leak from getting worse while you check the cause.
Can I clear a clogged condensate drain myself?
A wet or dry shop vac pulled at the outdoor end of the drain line clears many simple clogs. If the line stays blocked, the clog sits deeper in the coil or drain pan, and that needs a technician with the right tools to clear it without damaging the coil.
Why do AC drains clog more often on the Grand Strand?
Coastal humidity keeps the evaporator coil wet more hours a day than an inland climate does, which grows algae in the drain pan faster. Longer summer runtimes during peak cooling season push more condensate through the line, so a small buildup turns into a clog sooner here than elsewhere.
How fast can Comfort Masters come out for an AC leak?
Call (843) 443-7186 and we will get a technician scheduled and confirm timing when you call. The visit includes a full diagnosis with written findings, so you know what caused the leak before any repair is recommended.
Sources and references
Where these numbers come from
- ENERGY STAR: Heating and Cooling Maintenance Checklist
- U.S. Department of Energy: Home Cooling 101
- U.S. Environmental Protection Agency: A Brief Guide to Mold, Moisture and Your Home
Professionally reviewed by
Alex Todd
- ACCA Manual J/S/D standards
- EPA 608 Certified
- SC HVAC #38846
- NC HVAC #36196
Owner and lead HVAC technician at Comfort Masters Heating & Cooling, with two decades of coastal HVAC experience on the Grand Strand.
Reviewed: August 2026
AC leaking right now
Get it diagnosed before it spreads.
A leaking AC will not fix itself, and running it while it leaks risks water damage that costs more than the repair. Comfort Masters serves North Myrtle Beach, Little River, Calabash, Cherry Grove, Longs, Loris, Myrtle Beach, Sunset Beach, and Ocean Isle Beach with a full diagnostic and written findings before any repair is quoted.
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Service area
HVAC across the Grand Strand.
Comfort Masters Heating & Cooling provides coastal HVAC service across North Myrtle Beach and the Grand Strand from 3502 State Hwy 50 in Little River, SC 29566.
Comfort Masters Heating & Cooling 3502 State Hwy 50, Little River, SC 29566(843) 443-7186 Get directions
Areas we serve
- North Myrtle Beach
- Little River
- Calabash
- Cherry Grove
- Longs
- Loris
- Myrtle Beach
- Sunset Beach
- Ocean Isle Beach