AC Unit Drain Overflow Cleanup in Keller, TX

Is This What You Are Seeing in Your Keller Home?

• Water in the secondary pan. The lower pan is only a backup, so standing water in it means the main drain has failed.
• Rings on the ceiling. Brown rings under the air handler show water has passed through insulation into the drywall.
• Dripping vents or fixtures. Water at a register or ceiling light means condensate is running along ducts or joists.
• A house that will not cool. A tripped float switch shuts the AC down, which can point to a full pan.
• Peeling paint up high. Water moving down top plates bubbles paint where wall meets ceiling.
• A musty attic smell. An earthy odor near the attic hatch means insulation has stayed damp.

What to Know About AC Unit Drain Overflow Cleanup in Keller

In a typical Keller home the air handler and evaporator coil sit in the attic, right above bedrooms, hallways and closets. On a hot day that coil pulls gallons of water out of the indoor air, and a narrow PVC line carries it outside or to a drain. When algae, dust or a sagging section blocks that line, water backs into the primary pan, then the secondary pan, and finally over the edge onto the attic floor. Because almost nobody climbs into a summer attic, the first sign is usually a brown ring on the ceiling of the room below.

Condensate is clean water when it drips off the coil, but the path it takes matters. It soaks blown or batt insulation, which holds water against the ceiling drywall like a sponge. Wet drywall sags, loses strength and can drop in a sheet. Insulation and drywall that stay damp in a warm attic for several days begin to smell musty and can grow mold.

A local restoration crew treats the attic and the rooms below as one job. Technicians check the pans, the float switch and the drain line, then use moisture meters and a thermal camera on ceilings and walls to find the true edge of the wet area. Saturated insulation is bagged and removed, soft drywall is cut out, and air movers with a dehumidifier dry the framing and the materials that stay.

Keller summers are long and hot, so attic systems run hard for months and make condensate nearly every day from spring into fall. Many homes in Hidden Lakes, Marshall Ridge and the subdivisions off Rufe Snow Dr were built between the 1980s and the 2000s, and like other DFW homes of that era many put the air handler in the attic. Original pans and drain lines from those years are now old enough to rust, crack or sag.

Do These Things Before the Crew Arrives

1. 1
   Shut the system off Set the thermostat to off and flip the breaker for the attic air handler so the coil stops making water.
2. 2
   Stay clear of sagging drywall A bulging ceiling can hold a lot of water, so keep people and pets out of that room and do not touch wet light fixtures.
3. 3
   Relieve a growing bulge Set a bucket under the lowest point and pierce it with a screwdriver so the water drains where you want it.
4. 4
   Protect the room below Move beds, electronics and rugs out from under the wet spot and lay plastic or towels on the floor.
5. 5
   Check the backup drain A drip from the pipe above a window or eave means the main line is blocked.
6. 6
   Photograph and call Take pictures of the stain and any wet floors, then call to reach a local crew.

How a Keller Crew Handles AC Unit Drain Overflow Cleanup

1. 1

   Attic and pan inspection

   The technician climbs into the attic, inspects both drain pans, the float switch and the condensate line, and confirms the unit is off before any work begins.

2. 2

   Mapping the wet area

   Moisture meters and a thermal camera trace water across the ceiling, down wall cavities and into flooring, so the crew knows exactly which rooms and materials are affected.

3. 3

   Removing wet insulation

   Soaked blown or batt insulation over the leak is vacuumed or bagged and carried out, since compressed wet insulation dries slowly and keeps the drywall under it damp.

4. 4

   Opening damaged drywall

   Ceiling panels that sag, crumble or test very wet are cut back to sound framing, and wall drywall that wicked water is trimmed above the wet line.

5. 5

   Drying attic and rooms

   Air movers and a dehumidifier are set in the rooms below, and airflow is pointed at exposed joists and top plates until meter readings reach the dry target.

6. 6

   Final check and handoff

   Once readings are dry the equipment comes out, the work area is cleaned, and the homeowner gets notes to share with an HVAC technician about the drain line.

Why It Happens in Keller Homes

Algae in the drain line

Warm, wet PVC lines grow slime during long Keller cooling seasons until the flow stops.

Rusted primary pan

The metal pan built into older coils corrodes, and pinholes let water skip straight to the secondary pan.

Missing or failed float switch

Without a working switch the system keeps running while the pan overflows.

Sagging or pulled-apart line

A line that sags across joists holds water, and a joint bumped loose by someone moving through the attic leaks at the fitting.

Dirty filters and frozen coils

A clogged filter lets the coil ice over, and when the ice melts it can release more water than the pan can hold.

Most Keller neighborhoods went up between the 1980s and the 2000s, and like much of DFW they rely on slab-on-grade foundations with the furnace, air handler and often the water heater placed in the attic. That layout saves floor space but puts the equipment that makes the most water directly above finished rooms. In two-story homes around Hidden Lakes, an overflow can soak an upstairs ceiling, while in single-story homes near Old Town Keller it lands right above bedrooms and halls.

For this service, the attic is always part of the job, not just the stain below it. Because cooling runs from spring into fall here, a pan that overflowed once tends to overflow again until the line is cleared and a float switch is working.

What It Costs and How Long It Takes

How to Keep It From Coming Back

• Flush the line each spring. Flush the condensate line with water or a mild vinegar mix before the cooling season.
• Install a float switch. A switch on the pan or line shuts the system off before water spills over.
• Replace rusty pans. Swap a stained or rusted secondary pan before summer.
• Change filters on schedule. Clean filters keep the coil from freezing and dumping melt water.
• Watch the backup drain. A drip from the pipe over a window or eave is an early warning worth acting on.

AC Unit Drain Overflow Cleanup FAQs