Quick Answer:
If you hear a gurgling sound when the washer drains, it often means air is moving through the drain system because of a partial clog, a venting issue, or pressure changes in the line. First run a few simple checks yourself: run the washer alone, then run it while another fixture (like a sink) is used; watch nearby trap water levels and listen at the drain opening to tell if the noise is suction or pushback. If the sound keeps returning or more fixtures are affected, a plumber can inspect the venting and main line safely.
Why This Happens
Gurgling is usually a sign of air and water trying to share the same space. Common causes:
- Partial clog in the drain or main line causing air to be forced through trap water.
- Blocked or restricted vent pipes that prevent proper air flow, so drains pull air through traps.
- Multiple fixtures draining into the same branch line at once, creating pressure changes.
Recent work on vents or added vent accessories can change how air moves; if you recently changed venting, see Gurgling after installing vent device for more detail. If several fixtures act up at once, check Gurgling when multiple fixtures run.
Step-by-Step What to Do
1. Start with simple observation
- Run the washer alone and listen. Note whether the gurgle happens only while it drains.
- Run the washer again while someone else runs another nearby fixture (bathroom sink or tub). This checks how the system behaves under multiple loads.
2. Watch the traps
- Look at nearby floor or sink traps (the U-shaped parts under fixtures, or visible trap primer ports). Note whether the water level in those traps moves when the washer drains. Dropping water levels suggest suction; bubbling suggests air being forced back up.
3. Listen at the drain opening
- Put your ear near the drain opening while the washer drains (do not block the opening). A sucking sound or bubbling gives a clue: suction usually pulls air through traps; a pushback or active bubbling suggests air or water being forced back up.
4. Try basic clearing only if accessible
- If you see a slow drain and can access the trap, remove and clean the trap by hand to clear lint or hair. Use gloves and a bucket.
- Do not use chemical drain cleaners (see the next section).
5. Repeat the tests and note patterns
- Run the washer a few more cycles and note whether the gurgle is consistent, only during heavy loads, or only when other fixtures run.
- Take photos or notes of when it happens—this helps a plumber diagnose vent vs. clog issues.
What Not to Do
- Don’t pour harsh chemical drain cleaners down the drain—these can damage pipes, harm septic systems, and make later repairs worse.
- Don’t cap or seal roof vents or attempt to block vents blindly to stop noise—this can create dangerous sewer gas buildup and worsen drainage.
- If multiple fixtures are affected, don’t assume it’s only the washer—have a plumber check venting and main line conditions rather than trying DIY fixes that could hide a bigger problem.
When to Call a Professional
- When the gurgling continues after simple checks or returns regularly.
- If you smell sewer gas, see sewage backing up, or multiple fixtures gurgle at once—these can indicate a blocked vent or main sewer issue.
- If you’re uncomfortable working near traps, removing traps, or going onto the roof to check vents—plumbers have the proper safety gear and tools to inspect vents and the main line safely.
If the issue is intermittent but recurring, it’s reasonable to have a plumber inspect the venting and main line so the condition can be diagnosed before it becomes a larger backup.
Safety Notes
- Wear gloves and eye protection when handling traps or any wastewater.
- Avoid inhaling odors from drains—if you detect strong sewer smell, ventilate the area and consider leaving until a pro arrives.
- Do not climb on a roof alone. Leave roof vent inspection to professionals if you don’t have safe access and fall protection.
Common Homeowner Questions
- Is gurgling always a serious problem? Not always—sometimes a minor clog or air pocket will cause temporary gurgling. Persistent or widespread gurgling needs attention.
- Can I fix it myself? You can clear an accessible trap by hand, but avoid chemicals and vent work; call a plumber for persistent or multiple-fixture issues.
- Will a blocked vent cause backups? Yes—blocked vents can cause slow drains and traps to lose water, which may lead to sewer smells and backups if not addressed.
For more related articles, see the Gurgling Sounds From Drains or Fixtures hub.