AC Leaking Water Inside Your Home
Water pooling around your indoor unit? This is usually a drainage or airflow problem — here are the most common causes and what parts you may need.
Finding water around your indoor AC unit or furnace is one of the most common summer complaints we hear at the counter. The good news: most causes are straightforward and fixable with basic tools and the right parts. The evaporator coil naturally produces condensation during cooling — when that water can’t drain properly, it overflows. Let’s walk through the causes from most to least common.
Common Causes
Clogged Condensate Drain Line
MOST COMMON
The condensate drain line carries water from the drain pan to the outside. Over time, algae, mold, and debris clog it. When blocked, water backs up into the pan and overflows onto your floor. You can try flushing the line with a wet/dry vacuum or vinegar — but if the pan is cracked or the line is severely blocked, you may need replacement parts.
Condensate Drain Pans & Fittings
We carry drain pans, PVC fittings, condensate pump tubing, and drain line cleaning supplies.
Dirty Air Filter Causing Frozen Coil
VERY COMMON
A clogged filter restricts airflow across the evaporator coil, causing it to freeze. When the ice melts, the excess water overwhelms the drain pan and leaks onto the floor. Check your filter first — if it’s packed with dust, replace it and let the coil thaw completely before restarting.
Air Filters
Standard and high-efficiency filters in all common sizes. Bring your old one in — we’ll match it.
Failed Condensate Pump
If your indoor unit is in a basement, attic, or anywhere the drain pan sits below or level with the drain line exit, a condensate pump moves water upward and out. When the pump fails, water fills the pan and overflows. Test by pouring water into the pump reservoir — if the float rises but the pump doesn’t kick on, it needs replacing.
Condensate Pumps
Little Giant and universal condensate pumps in stock. Bring your old pump in for a match.
Rusted or Cracked Drain Pan
Older systems (10+ years) often develop rust holes or cracks in the primary drain pan. Even small cracks will leak water directly onto your floor or ceiling. Most systems have two drain pans — a primary under the coil and a secondary (safety) pan under the entire air handler. If the secondary pan is catching water, the primary is likely damaged.
Drain Pans
Replacement drain pans in common sizes. We can help match one to your system.
Disconnected or Damaged Drain Line
PVC drain lines can crack, come loose at joints, or get knocked off during filter changes or other maintenance. If the line is disconnected, water drains directly onto the floor instead of being carried outside. Check every joint and connection from the drain pan to where the line exits your home. Re-glue loose PVC fittings or replace cracked sections.
PVC Fittings & Supplies
PVC elbows, couplings, cement, and drain line accessories in stock.
💡 Check First
Before chasing complex causes, check your air filter and look at the drain line exit outside your home. If water isn’t dripping from the drain line while the AC runs, the line is likely clogged. You can often clear it with a wet/dry vacuum on the outside end. Also look for ice on the copper lines near the indoor unit — if you see frost or ice, the coil is freezing and you have an airflow problem.
✅ Quick Diagnostic Checklist
- Check your air filter — is it clogged or dirty?
- Look at the drain line exit outside — is water dripping while AC runs?
- Check for ice or frost on refrigerant lines near the indoor coil
- Inspect the drain pan under the coil — any visible cracks or rust?
- If you have a condensate pump — pour water in the reservoir to test it
- Trace the PVC drain line — any loose joints or disconnections?
- Check if the secondary (safety) drain pan has water in it
⚠️ Safety Note
Water and electricity are a dangerous combination. Always turn off your system at the thermostat and breaker before working near the indoor unit, drain pan, or any electrical connections. If water has reached electrical components, wiring, or outlets, shut off power immediately and call a professional. Mop up standing water promptly to prevent floor damage and mold growth.
Need the Right Part?
Bring in your old part or model number — we’ll match it and test it at the counter. Free.
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