AC Unit Drain Overflow Cleanup in Renton, WA

What to Know About AC Unit Drain Overflow Cleanup in Renton

Every air conditioner, heat pump and high-efficiency furnace makes water. In most homes that water drains through a small plastic line to a floor drain, a laundry standpipe or a condensate pump. When the line clogs with slime or the pump quits, the drain pan fills and spills over its edge a little at a time. Equipment tucked into a hall closet, a garage corner, an attic or the crawlspace under a rambler can leak for days before anyone looks, and by then the water has crept into flooring, drywall and framing.

Condensate starts out as clean water, but it rarely stays where it lands. Under an attic air handler it soaks insulation and stains the ceiling below. In a closet it slides under the bottom plate and into hallway carpet or laminate. In a crawlspace it pools on the vapor barrier where nobody sees it and raises humidity under the whole floor. Water that sits warm and dark for several days begins to smell and can lead to mold on drywall paper, subfloor and joists.

A local restoration crew starts by finding the source and the outer edge of the wet area with pin and pinless moisture meters and a thermal camera. They extract standing water, lift or pull pad when carpet is involved, cut drywall that wicked above a safe line and open baseboard cavities. Air movers and a dehumidifier sized to the room go in next, and readings are logged on each visit until materials match a dry reference.

Renton summers are dry, and August is usually the driest month, so cooling systems run long cycles exactly when drain lines grow algae. Homes in Benson Hill, Fairwood and the Highlands that run a heat pump or high-efficiency furnace also make condensate in winter, and a line routed through a cold garage or crawlspace can freeze during an arctic cold snap and back up into the pan.