What it usually means
Listen for which drain gurgles and what you were doing when it did. That tells you most of what you need to know.
| One sink gurgles as it empties | A partial blockage just past that sink's trap. Water goes down in gulps. It will get slower. |
|---|---|
| The tub gurgles when the toilet flushes | Those two share a drain, and it is either partly blocked past where they join or it has lost its vent. |
| The toilet bubbles when the washer drains | A restriction in the main line. The washer sends a lot of water at once and the air has to go somewhere. See toilet bubbles when the shower runs. |
| Every drain gurgles, worst at the lowest floor | The main sewer line is closing up. This is the early warning before a backup. |
| Gurgling with a sewer smell | A trap is being sucked dry, which lets sewer gas in. See sewer smell in the house. |
What to check yourself
- Fill the gurgling sink and let it go. If it drains slowly and gurgles at the end, the blockage is local to that sink.
- Flush the lowest toilet in the house while someone watches the tub or shower beside it. Movement in the tub drain means a shared restriction.
- Run water into any drain you rarely use, like a basement floor drain or a spare shower. A dry trap gurgles and smells.
- From the ground, look at the roof vent. A bird nest, leaves or frost over the top will do it. Do not go up on a wet roof to check.
Call before it backs up if
- More than one fixture is gurgling
- The lowest toilet bubbles when water runs elsewhere
- Gurgling started after heavy rain
- A drain that gurgled is now slow
Call 1-800-604-0631, any hour.
What fixing it costs
It depends where the restriction is. A single fixture is a flat clog price: from $269 for a toilet, from $329 for a sink, tub or shower. A main line is from $649. Those are regular-hours prices (9 to 5, Monday to Friday). Outside those hours every price is double. Each covers up to 2 hours on site, and the drain is tested in front of you before we leave.
If nothing is blocked and the vent is the problem, that is hourly work: $289 for the first hour on site and $189 an hour after that. See stack cleaning.
Questions people ask
Is a gurgling drain an emergency?
Not by itself. A gurgle in one sink can wait for regular hours. Gurgling from several drains, or a bubbling basement toilet, means a backup is coming and is cheaper to deal with before it does.
What does the vent actually do?
Water falling down a pipe pushes air ahead of it and pulls air behind it. The vent lets that air in from the roof. Without it, the pipe pulls air through the water in the nearest trap, which is the gurgle.
Can I clear a roof vent myself?
We would not. It means working at the roof edge, and a hose down a vent can flood a wall if the blockage is lower than you think.