AC leak water damage happens when the water an air conditioner normally removes from your indoor air ends up somewhere else. Cooling a house wrings moisture out of the air, and that condensate is supposed to leave through a drain line. When the line clogs, the pan cracks or the coil ices over and thaws, the water goes into the ceiling, the closet or the floor.
In Littleton, CO the dry climate makes this less dramatic than in humid states. NWS Boulder puts the metro's normal annual precipitation at 14.48 inches, so a stain after a hot week is more likely to be condensate than rain. Many Front Range homes also use evaporative coolers, and central air leaks are a real but modest share of what we see.
Where AC leaks start in a house
The usual culprits are the condensate drain line, the drain pan under the air handler, and the evaporator coil. Algae and dust build a slime plug in the drain line, and the pan overflows. A coil that froze from low airflow or a dirty filter can thaw all at once and overwhelm the pan.
The location of the air handler matters most. In an attic or a second-floor closet, a small overflow lands on drywall and insulation. In a basement utility room, the same overflow reaches a concrete floor and does less harm.
| What you see | Likely cause | What it affects |
|---|---|---|
| Brown ring on a hallway ceiling | Overflowing drain pan above | Drywall and attic insulation |
| Dripping from the indoor unit | Clogged condensate line | Closet floor and baseboard |
| Ice on the coil or lines | Low airflow, then a heavy thaw | Pan overflow and nearby framing |
| Musty air with the system running | Damp insulation or duct wrap | Attic and duct runs |
| Sagging ceiling tile or board | Water held above the drywall | Ceiling, insulation, joists |
Safety steps when an air handler leaks
- Turn the thermostat to off and switch off the breaker for the air handler. Running a unit with a clogged drain pushes more water out.
- Do not touch the unit or stand in water if the closet or attic floor is wet. Power and water together are a shock risk.
- Catch what you can with a bucket or towels below the drip, and place plastic on furniture beneath a stained ceiling.
- If the ceiling is bulging, keep people out of the room. A sagging board can fall and should be relieved by a trained crew.
- Call an HVAC contractor for the unit and call us for the water.
A bulging ceiling is a safety issue
Water trapped above a ceiling is heavy and can bring the board down. Stay out from under it, and do not poke it open yourself.
How we dry and repair after an AC leak
Find the wet area
Moisture meters and a thermal camera map the ceiling, walls and attic insulation.
Relieve and remove
Saturated drywall and insulation come out, and trapped water is drained in a controlled way.
Dry the cavity
Air movers and dehumidifiers run on the ceiling cavity, joists and floor below.
Check duct wrap
Wet insulation around ducts and the closet floor is inspected, since damp materials can feed mold.
Hand off to repair
When readings reach target, the ceiling and finish work move to the repair phase.
We dry and repair the water damage but we do not repair air conditioning equipment. The HVAC contractor clears the line, replaces the pan or services the coil. Until the cause is fixed, the leak will return, so schedule both trades together.
Water coming through a ceiling near your AC? Call and describe where the unit sits.
Call (303) 952-8295What changes the cost of AC leak damage
- How long the line dripped before it was noticed.
- Whether the water reached an attic, a closet or a living space.
- How much ceiling drywall and insulation was soaked.
- Whether flooring below the leak was wet.
- How many days the drying equipment must run.
We explain scope and price at the start, and we tell you if opening the ceiling changes the plan.
Insurance and the AC leak
Colorado Division of Insurance advisories say most property policies handle sudden and accidental water damage differently from long-term seepage. A condensate line that clogged and overflowed over a weekend may be treated as sudden, while a drip that ran all season may be treated as gradual. Ask your insurer how it classifies your case, and get its instructions before repairs.
Prevention before the cooling season
- Have an HVAC contractor flush the condensate line before summer.
- Change the filter on schedule so the coil does not freeze.
- Add a float switch that shuts the unit off if the pan fills.
- Do not ignore a small ceiling stain after the system runs.
Littleton, CO: climate, permits and contractors
NWS Boulder lists Denver's normal annual precipitation at 14.48 inches, so rain is a less common indoor water source in summer than a clogged AC drain. When you see a ceiling stain in July with no storms, check the air handler first.
The City of Littleton Permit Center requires a permit to install, alter, repair or replace any mechanical system. If your HVAC contractor replaces the unit or alters ducts, ask whether a permit is needed, and ask for the contractor's Littleton license.
Colorado DORA's consumer page says not all occupations are licensed. The city requires proof of liability insurance from contractors who pull permits, so confirm it before the work starts.
Sources: NWS Boulder annual summary, Littleton Permit Center page, Colorado DORA consumer page, City of Littleton contractor licensing information.
Our water mitigation crews handle the first drying steps, and once the readings are dry the finish work moves to water damage repair. If damp insulation stays wet for several days, mold remediation may enter the plan.
We also dispatch to homes in Lone Tree and Aurora where attic and closet air handlers cause the same ceiling stains. Drying goals follow ANSI/IICRC S500, the published standard for water damage restoration.
Common questions
Yes. A drain pan that overflowed above a ceiling is worth a night call. We dispatch when a crew is available and give no arrival promise. The dispatcher will explain how to switch the system off and protect the room below.
No. Switch the system off until an HVAC contractor clears the drain, because running it sends more water to the same spot.
No. We dry and repair the house. An HVAC contractor repairs the unit, clears the drain line or replaces the pan.
The water source differs, since evaporative coolers add water to cool the air. We dry the damage either way, and the cooler's own line or pan needs a technician.
Damp insulation and framing can support mold if they stay wet. Fast drying is the best protection, and health questions belong with a physician.