Short answer
Water around the air handler is usually a clogged condensate drain: the line that carries away the moisture your AC pulls out of the air. If water is near any wiring or outlet, shut the power off at the breaker first. Then check the drain pan and line. A frozen coil that's melting, a cracked pan, or a disconnected drain are the other usual causes.
What's probably happening
Humidity is a big deal in the Upstate. On a muggy summer day your AC wrings a lot of water out of the air, and all of it has to go somewhere. It drips off the indoor coil into a pan, then out through a drain line, usually to the outside or into a pump. If anything in that path fails, you get water where it shouldn't be. In attics, that means a ceiling stain. In crawlspaces, it can mean standing water nobody sees for a while.
A clogged drain line
Algae and sludge grow in the dark, wet line and plug it. This is the most common cause by a long way.
A frozen coil melting
When an iced-up coil thaws, a lot of water hits the pan at once and can overflow it. If you also have weak airflow or ice on the lines, see the frozen AC page.
A cracked or rusted pan
Older metal pans rust through. Plastic pans can crack. Either one leaks even when the drain is clear.
A failed condensate pump or a disconnected line
Some systems pump the water out. When the pump fails, the water stays. Drain lines can also come apart where they join.
Sweating ducts
Cold ducts in a humid crawlspace or attic can sweat and drip, especially if the insulation is torn or missing.
What you can check yourself in five minutes
- If water is anywhere near the unit's wiring, a switch, or an outlet, turn the system off at the thermostat and switch off its breaker before going near it.
- Look at the pan under the indoor unit. Is it full? Is the float switch on the pan or drain line tripped? If so, that's why cooling stopped.
- Find where the drain line ends outside. On a humid day with cooling running, it should be dripping. If it's dry, the line is likely clogged.
- If you have a condensate pump, check that it's plugged in and see whether its reservoir is full.
- Soak up standing water with towels or a wet-dry vacuum, and move anything that can be damaged.
- Replace the air filter. A dirty filter can freeze the coil and lead to a flood when it melts.
- Look for ice on the copper lines. If there's ice, leave cooling off and run the fan.
If you can reach the end of the drain line outside, a wet-dry vacuum held on it for a minute can sometimes pull the clog out. Don't take panels off the unit to get at it.
When to stop and call
- Water is on or near electrical parts, wiring, or an outlet. Power off at the breaker first, then call.
- Water is coming through a ceiling. Turn the system off to stop adding more.
- The pan keeps filling after the drain has been cleared.
- There's ice on the coil or lines.
- A breaker trips again after one reset, or you smell burning.
Please don't bypass or remove the float switch to keep the AC running. It's what's protecting your ceiling. If you're in Spartanburg or Greenville County, call Alpine Cool at (864) 702-0777.
Common questions
Why is there water around my AC unit inside the house?
Your AC pulls a lot of moisture out of the air, and that water is supposed to run out through a drain line. When the line clogs with algae and sludge, the water backs up into the pan and overflows. A clogged drain is the most common cause.
Why did my AC stop cooling when the pan filled up?
That's the float switch. It senses water backing up and shuts the system off so it doesn't overflow into your ceiling or floor. Clearing the drain usually lets it restart. Don't bypass the switch.
Is water from my furnace in winter normal?
Some high-efficiency gas furnaces make condensate and drain it through a line, so a drain line with water in it can be normal. Water on the floor is not. A heat pump can also drip during defrost outside, which is normal.
How do I keep the drain line from clogging again?
Change the filter on schedule, and have the drain line and pan checked during regular maintenance. Some systems have an access port on the line that makes flushing easier.