Why is my air conditioner condensation pan overflowing?
Condensation drain pans fill up and overflow repeatedly, forcing people to constantly shop vac standing water to prevent property damage and leaks. Because the underlying causes are hard to pinpoint, homeowners and renters get stuck dealing with recurring indoor flooding.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Having the landlord or an HVAC company clear the drain line
- 2Putting preventative tablets in the pan
- 3Installing a kill switch to shut off the system when water builds up
- 4using a shop vac to remove standing water
- 5cleaning grime and clearing pipes
- 6pushing PVC pieces around the P-trap to tighten fixtures
- 7Take the trap and turn it up a little more
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“For the second time we got a leak caused by the condensation pan filling up.”source ↗
“Trap might not be deep enough and the air suction is holding the water in. Can cause big floods from roof top units into the ceiling.”source ↗
“Our drain pan has been filling up recently where I've had to shop vac the standing water twice in the 2 weeks so I've been trying to determine the root cause and apply a fix”source ↗
“I don’t understand is this normal or is there an issue with the draining and water backing up?”source ↗
Where this came up
People with this problem also raised
- 29How to clear a clogged AC condensate drain line
- 2Is air conditioner condensation normal or a leak?
- 10Why are my new gutters leaking from behind?
- 10Why is my AC air handler wet and smelly?
- 6What is this extra pipe dripping into my sink drain?
- 10Why is water backing up into the sink when appliances drain?