AC Troubleshooting
AC Leaking Water in Brooklyn — Causes & Fixes
Water dripping from your indoor AC is almost never normal. In Brooklyn brownstones and walk-ups it's usually one of four things — and the fix depends on which. Here's how to tell, and when to shut it off.
Anatomy of the system
Numbered parts below match the cost table further down — so you can see exactly where the failure usually sits.
- 1Algae clog in PVC condensate line (most common)
- 2Sagging line holding standing water
- 3Rusted-through drain pan under air handler
- 4Frozen evaporator coil thawing into the pan
Step-by-step troubleshooting
Run through these in order. The DIY checks are safe; the red callouts mean stop and call us.
- 1
Shut the system off if water is reaching ceilings or walls
If you're seeing water spread on a ceiling or wall, kill the AC at the thermostat first. Continued runtime makes the leak worse and can short out controls below.
Stop and call us
Active ceiling water, sparking outlets, or burning smell — power the system off at the breaker and call (347) 997-3360. Don't keep running it. - 2
Check the air filter
A clogged filter restricts airflow across the evaporator coil, the coil ices up, then thaws into a pan that can't keep up. This is the #1 reason a healthy AC suddenly drips.
Try this before calling
- Pull the filter — if light won't pass through it, replace it
- Run on FAN ONLY for 30–60 minutes to thaw any ice
- Restart in COOL and watch for drips for 10 minutes
Still not working? Call (347) 997-3360 — diagnostic visits are flat-rate and credited toward the repair.
- 3
Look at the condensate drain line
The PVC line carrying condensate from the air handler is the #1 cause of long-term leaks. Brooklyn humidity grows algae fast, and the line clogs near the trap or at the exterior exit.
Try this before calling
- Find the white PVC pipe leaving the air handler
- If you can reach the exterior exit, check that water actually drips out when AC runs
- A wet/sweet smell near the indoor unit means a partial clog
Still not working? Call (347) 997-3360 — diagnostic visits are flat-rate and credited toward the repair.
- 4
Check for a frozen coil
Open the air handler cover. A solid sheet of ice on the indoor coil means low refrigerant, weak airflow, or a failing blower. This is a real diagnostic — not a DIY fix.
Don't keep running a frozen system
Running with a frozen coil can damage the compressor — a $1,800–$3,500 repair. Shut it off, let it thaw, and call us to find why it froze.
What this usually costs in Brooklyn
Real-world ranges for Brooklyn homes. The exact number depends on parts, access, and how long it's been failing.
| Issue | Likely cause | Typical range |
|---|---|---|
| Clear clogged condensate line | Algae buildup in PVC | $185 – $325 |
| Replace rusted drain pan | Long-term overflow corrosion | $425 – $750 |
| Diagnose & recharge low refrigerant | Leak causing frozen coil | $525 – $1,250 |
| Replace condensate pump | Failed pump on basement air handler | $385 – $625 |
| Re-pitch sagging drain line | Improper original install | $450 – $900 |
Clear clogged condensate line
Algae buildup in PVC
$185 – $325
Replace rusted drain pan
Long-term overflow corrosion
$425 – $750
Diagnose & recharge low refrigerant
Leak causing frozen coil
$525 – $1,250
Replace condensate pump
Failed pump on basement air handler
$385 – $625
Re-pitch sagging drain line
Improper original install
$450 – $900
Typical range. Final cost confirmed on site after diagnosis.
Common Questions
Related Brooklyn HVAC services
Need a Brooklyn tech today?
Same-day diagnostics when we can fit you in. Flat-rate visit, credited toward the repair.
(347) 997-3360