Quick answer
A gurgling drain means air is being pulled through the trap because water cannot drain normally: a partial clog in that fixture, a clog in a shared branch line, a blocked roof vent, or a main sewer line clog. One gurgling sink is usually its own clog; several gurgling fixtures, or a tub that gurgles when the toilet flushes, point to the branch or main line. HomeServe puts drain cleaning at $100–$275. Call (888) 217-6781 to reach a plumbing company taking calls in your ZIP.
Follow the short menu, then your 5-digit ZIP. The line goes quiet for a few seconds while it connects; stay on. If it does not connect, call once more: companies taking calls change minute to minute.
Written & reviewed by Marcus ReedIICRC WRT
Reviewed November 4, 2026· Next review May 2027
A gurgling drain is air being pulled through water in the trap. That happens when the water leaving the house cannot draw air in the normal way: either a partial clog is slowing it, or the vent pipe that lets air into the drain system is blocked. Which fixtures gurgle, and when, tells you where to look.
Read the Pattern
| What you notice | Likely cause |
|---|---|
| One sink gurgles as it drains | Partial clog in that fixture's drain or trap |
| Tub or shower gurgles when the toilet flushes | Clog in the shared branch drain |
| Toilet gurgles when the washer drains | Branch or main line clog, or a blocked vent |
| Several fixtures gurgle and drain slowly | Main sewer line clog |
| Gurgling with a sewer smell, drains flow fine | Blocked or missing vent, dry trap; see bathroom smells like sewer |
| Gurgling after heavy rain | Ground water in a cracked sewer line, or a city main backing up |
Check These First
- 1Clear the fixture itself. Pull the sink stopper or shower strainer and clean it, then plunge with the overflow covered. See bathroom sink not draining.
- 2Run water in one fixture at a time and listen at the others. Gurgling somewhere else points to a shared line.
- 3Look at the roof vent from the ground. Leaves, a bird's nest or, in winter, frost can close the opening. Do not go on the roof to clear it yourself.
Talk to a plumber about this
One call reaches a plumbing company taking calls in your ZIP.
Why Not to Wait
A main-line clog that gurgles today can back sewage into the lowest drain in the house tomorrow, usually a basement floor drain or a ground-floor shower. If several fixtures gurgle at once, use as little water as you can until the line is cleared.
What a Repair Costs
HomeServe puts drain cleaning at $100–$275 and a main-line clog at $150–$500. A vent clearing is usually priced like a drain cleaning; a camera inspection of the sewer line is extra. See drain cleaning.
When to Call
Call if more than one fixture gurgles, if a drain backs up when another is used, or if you smell sewage. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP. Follow the short menu, enter your 5-digit ZIP and stay on while it connects; if it does not connect, call once more, because the companies taking calls change minute to minute.
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Frequently Asked Questions
Why does my drain gurgle?
Water leaving the drain is pulling air through the trap, because a partial clog or a blocked vent stops air reaching the drain the normal way.
Why does my tub gurgle when I flush the toilet?
The two share a branch drain, and a clog in it, or in the main sewer line, forces air back up through the tub.
Is a gurgling drain serious?
One gurgling sink usually is not. Several gurgling fixtures can mean a main line clog that backs sewage into the lowest drain, so call a plumber if more than one fixture is affected.
Sources
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Disclaimer: HearthDry is an independent educational resource. This article is for informational purposes only and does not constitute professional, legal, or insurance advice. Consult licensed professionals before making decisions about your property or insurance claims.