An air conditioner pulls a surprising amount of water out of the air on a humid day. That water is supposed to drip into a pan under the indoor coil and run away through a small drain line. When you find water where it shouldn't be, something along that path has gone wrong.
First: protect the house
- Turn cooling off at the thermostat so no more water is made.
- Mop up, and put a towel or bucket under any drip.
- If water is coming through a ceiling below an attic unit, or near light fixtures or outlets, turn the system's breaker off too and call.
The usual causes
A clogged drain line
The most common cause by far. Over time the drain line collects slime, dust and algae and stops flowing, so the pan fills and overflows. Many systems have a safety switch that shuts cooling off when the pan fills, which is why a leak and a system that "just stopped" often go together.
A frozen coil that's thawing
A dirty filter or low refrigerant can let the indoor coil ice over. When it thaws, more water arrives than the pan can handle. If you see ice on the copper lines, see why your AC is blowing warm air.
A cracked or rusted drain pan
Older systems, especially in attics, can have pans that have rusted through or cracked.
A condensate pump that's stopped
Where the drain can't run downhill, a small pump lifts the water out. If the pump fails, its reservoir overflows. You'll usually find it near the indoor unit, a small box with a tube coming out.
Sweating ducts or lines
Uninsulated or poorly insulated ductwork and refrigerant lines can sweat and drip in humid weather, sometimes far from the unit itself.
What you can check
- The filter. Replace it if it's dirty.
- The pan. If you can safely see it, is it full? A wet-dry vacuum can clear standing water.
- The condensate pump, if you have one: is it plugged in, and does it run when you lift its float?
Leave the coil, the refrigerant and anything electrical to a technician.
Preventing it
Clearing the condensate drain and pan is part of every maintenance visit, and it's one of the main reasons a yearly tune-up pays for itself. Our maintenance plan reminds you when it's due.
If it's leaking now, call us at 805-965-6326 or send us a message.
Related
More tips on cooling.