Few things are less unsettling than when you are washing dishes in your kitchen or brushing your teeth in the bathroom, and you suddenly hear a gurgling noise from down in your sink drains. While not dangerous, it could indicate a problem with your plumbing system. But what causes this strange sound, and how do you fix it?

What Does a Gurgling Drain Mean?

A gurgling drain usually indicates a plumbing issue where air becomes trapped or forced through water in your pipes. It’s the plumbing equivalent of your stomach growling — a signal that something is out of balance in the system.

Common Causes of a Gurgling Drain

Partial Blockages

Gurgling could indicate that you have a clog in the early stages of formation. When drain clogs begin to form, they tend to trap air pockets that can bubble up through the water. If you hear gurgling but haven’t had water backup yet, the clog may be easy to remove.

Fix: Try using a drain snake or flushing your drain with a mixture of baking soda and vinegar or hydrogen peroxide. You could also use boiling water, which can break up grease and soap scum.

Blocked or Clogged Vent Pipes

Your house has drain vents that prevent sewer gases and air pressure from building up in your drain pipes by diverting the gas through pipes in your roof. If these vents get blocked by birds, nests, leaves, and other debris, air gets trapped in the system, causing gurgling noises as it tries to escape through the drain.

Fix: You may have to climb on the roof and clear the vent pipe — which may be best done by professionals. 

Improperly Installed Drainage Systems

If your plumbing wasn’t installed correctly, it may not have the correct slope or venting needed to let air flow and water drain. Air pockets and poor drainage can lead to a gurgling noise. 

Fix: A licensed plumber can access your system, find the issues, and recommend necessary corrections. 

Faulty P-Trap

If a P-Trap isn’t working right, it could mean there’s a lack of water in it. If you smell bad sewer odors and gurgling sounds, you could have a problem within this system. 

Fix: Start by loosening the slip nuts on either side of the trap to inspect them for damage or debris and replace worn gaskets. Make sure you don’t over-tighten the slip nuts when putting the pipe back together. 

Damaged Drain Lines

Cracked or broken drain lines can lead to leaks, disrupted water flow, and, ultimately, gurgling sounds. If a sewer line has a blockage or break, sewer gases can be forced back up through the lines, which can also cause concerning sounds. 

Fix: A damaged drain line should be repaired or replaced as soon as possible to restore proper water flow and prevent gurgling sounds. 

Main Sewer Line Issues

If a sewer line has a blockage or break, sewer gases can be forced back up through the lines, which can also cause gurgling sounds. 

Fix: A broken sewer line is a severe problem as it could lead to sewage backing up into your house. Call a professional plumber to do an inspection and repair the damage or use hydro-jetting to remove a blockage. 

Accumulated Grease 

Grease can solidify in your pipes, narrowing the amount of space water can flow. Over time, it can collect other debris and lead to the slow drainage that causes gurgling noises. 

Fix: You can try clearing the drain with boiling water, dish soap, baking soda and vinegar, or a drain snake. If this doesn’t work, you may need your drain professionally cleaned. 

Septic Tank Problems

If you use a septic tank and have issues such as overfilling or neglecting regular maintenance, you could experience gurgling sounds in your drains. These noises are often the first sign that the tank needs attention. 

Fix: You should perform regular septic tank checks and pumping to prevent issues. You should also make sure you have the correct bacteria in your system. But if you think there’s a bigger problem, you may need your septic tank inspected by a professional plumber. 

How to Prevent Gurgling Drains

To prevent gurgling drains and any issues we’ve discussed above, make sure you:

• Avoid dumping grease or food scraps down the drain.
• Use drain screens to catch hair and debris.
• Schedule regular plumbing inspections.
• Get your vents professionally flushed with water.

A Gurgling Drain Could Mean You Have a Bigger Issue

You might think a gurgling drain, while unsettling, is no big deal. However, it could mean you have a bigger issue with your drains or plumbing system. Whether you have a simple clog or a more serious vent or sewer issue, acting quickly can keep your home running smoothly — and quietly.