Why is my double kitchen sink draining so slowly?
Water backs up in both basins while running the faucet even though the drain appears clear. People often suspect a double P-trap or a plumbing configuration issue, but standard fixes like clearing the lines frequently leave the slow draining unresolved.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1snaking the drain
- 2replacing the studor vent (air admittance valve)
- 3installing a continuous waste kit instead of individual traps
- 4Cleaning out hair
- 5Considering removing the U-connections and replacing them with a properly sloped continuous connection.
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“bathroom sink drains fills and drains slow.”source ↗
“when I am doing manual dishes the drain on both sink would be very slow when I am running the water to rinse.”source ↗
“Is it because of the double P trap? My drain is clear. help”source ↗
“No major change when I’ve done that”source ↗
“Done that several times, no real change”source ↗
Where this came up
People with this problem also raised
- 9Why is my brand new kitchen sink draining so slowly?
- 12Why is a newly installed sink drain leaking above the trap?
- 2Can you convert a double sink to a single without replacing the countertop?
- 10Why is water backing up into the sink when appliances drain?
- 15Why does my sink drain keep clogging up?
- 12How to fix a glued sink drain pipe