Quick Answer:
If several drains gurgle while the washing machine is running, stop all water use immediately and turn off the washer. This often means a blockage or surge pressure in the main sewer line or a full municipal connection. Locate the basement or exterior sewer cleanout and check it before running more water. If you see sewage at the cleanout, avoid adding more water and call a professional.
Why This Happens
When multiple fixtures gurgle at once — sinks, tubs or basement floor drains — the problem is usually downstream of the house drains. Common causes include a main-line clog, roots in the sewer pipe, a municipal sewer backup, or trapped air moving through the system as the washer forces water into a partially blocked line. For other similar situations see Multiple drains clog suddenly or Multiple drains flood at night.
Step-by-Step What to Do
1. Stop all water use and shut off the washing machine
- Turn the washing machine off and unplug it if possible. Do not run more loads.
- Close tap handles and avoid flushing toilets until you check the cleanout.
2. Find the sewer cleanout
- Locate the basement or exterior sewer cleanout. It looks like a capped pipe at floor level, in the yard near the foundation, or near the property line.
- If you’re unsure where it is, check near the foundation, in the utility area, or where the sewer line exits the house.
3. Check the cleanout carefully
- Put on heavy-duty gloves and eye protection.
- Stand to the side (not directly over the cap) and slowly loosen the cleanout cap a little to relieve pressure. Do this gradually so any trapped air or sewage releases in a controlled way.
- If you hear a strong hiss or see liquid, back away and open very slowly. If it’s just air, you may hear a release and no sewage.
4. If you see standing sewage at the cleanout
- Do not flush toilets or run more water. Avoid adding any water to the system.
- Document the level with photos or notes so you can tell a plumber or the utility company what you observed.
5. Perform a small drain test after the cleanout check
- After confirming the cleanout is clear or only had air pressure, run a small amount of water at one nearby fixture (a sink or tub) to see if it drains normally and whether gurgling continues.
- Use only a cup or a slow trickle — don’t run large volumes. If gurgling returns or sewage appears, stop immediately and call for professional help.
What Not to Do
- Do not pour chemical drain cleaner into several backed-up fixtures—this can worsen main-line clogs and corrode pipes.
- Do not open the cleanout quickly or stand directly over it; pressure releases can spray contaminated material.
- Do not keep running the washing machine or flush toilets if the cleanout shows standing sewage; that will push more sewage into the house.
- Call a pro when sewage appears at the cleanout or you can’t reduce the level safely.
When to Call a Professional
- Anytime you see sewage at the cleanout.
- If loosening the cleanout cap releases pressure you can’t safely control, or you’re unsure what to do next.
- If small drain tests fail or gurgling returns after stopping water use.
- If you suspect a municipal backup (multiple homes affected) — contact your sewer authority and a plumber.
Safety Notes
- Wear gloves and eye protection when opening the cleanout; sewage can contain harmful bacteria.
- Stand to the side when loosening caps, and open slowly to relieve pressure.
- Keep children and pets away from contaminated areas and wash hands thoroughly after any contact.
- If you feel unsure or encounter strong sewer gases, leave the area and call a professional.
Common Homeowner Questions
- Why are multiple drains gurgling? — Air trapped behind a partial clog or backpressure from a main-line obstruction is the usual cause.
- Does gurgling always mean the main sewer line is broken? — Not always; it often indicates a blockage or backup, but a broken line is one of several possibilities.
- Can I fix this with a plunger or snake? — Try only for a single fixture; if multiple drains are affected or sewage appears at the cleanout, stop and call a professional.
More in this topic
For more related fixes and similar symptoms, see Multiple Fixtures Backing Up Together.