Why Does My Sink Gurgle When I Flush the Toilet?

As an Amazon Associate, I may earn from qualifying purchases at no extra cost to you.

If the sink gurgles when you flush the toilet, then you know it spells trouble in your plumbing system and calls for an immediate fix or else expensive repair and maintenance costs from the plumber guy.

When you flush the toilet, the water flows through the pipes and creates a high-pressure zone. This high-pressure zone may force air out of the traps in the fixture, causing gurgling of your sink. The gurgling sound is an indication that there is a problem with your plumbing system. The main reason your sink is gurgling is because you have a partially or completely blocked drain.

If the blockage is in the main sewer line, all of your drain pipes connect to it, and this can cause the sink trap to pull in the vacuum air. Another possible reason is that the vent system is blocked. Lastly, a damaged or blocked P-trap can also cause gurgling.

To fix the issue, you can try to clear the blockage in the drain or sewer line. If the problem persists, it’s best to contact a professional plumber to help you identify and fix the problem.

Why Does My Sink Gurgle When I Flush the Toilet?

When the sink gurgles after flushing the toilet, then it means there could be one of the causes affecting your plumbing system. Therefore, it’s important to troubleshoot each one at a time and see whether the problem is fixed.

Why Does My Sink Gurgle When I Flush the Toilet?

1. A Clog in the Plumbing System

If your sink is gurgling, there’s probably a blockage.

There may be a blockage in the drain pipe near your toilet. The most common cause for these clogs is when the people in your household flush the wrong things down the toilet. When this kind of drain clog occurs, a backed-up and flooded toilet is often the first sign. A plunger is often all that is needed to clear out this clog.

The second possible location for a blockage is deeper in the sewage systems. The blockage is either in the main sewage line that links to your community’s sewer system or in the home’s venting stack. The vent stack is the conduit that goes through the roof to discharge sewage gas.

If you suspect a clogged toilet, the initial and most effective step to resolve the issue yourself is by using a plunger.

  • Firstly, close off the drains in nearby sinks to enhance the pressure when using the plunger. This closure ensures that the force exerted by the plunger is concentrated on the blockage in the pipes. Sealing off the sink drains completely using duct tape is recommended for optimal air pressure.
  • Next, please select a suitable plunger (consider checking out top-reviewed plungers) and vigorously pump it into the toilet around 10 to 15 times.
  • Following the plunging, reopen the sink(s) and attempt to flush the toilet again. If there’s no gurgling sound from the sink, you’ve likely resolved the issue. However, if the gurgling persists, continue plunging to dislodge any potential blockage.
  • If the plunger doesn’t clear the clog, consider using an auger, also known as a “plumber’s snake.” These tools are effective in removing clogs that plungers might not be able to handle.

If the obstruction cannot be cleared by either the auger or the plunger, it is probably too deep for them to reach. The issue cause could be accessible with a longer motorized instrument. To get to the cause of the problem, however, a different strategy will be required if the blockage is further inside the sewage systems.

2. Blocked Toilet Ventilation

If you follow the procedures listed, you should be able to remedy this issue even if you have no plumbing experience. This becomes especially crucial if the problem arises on the weekend when it might be impossible to get in touch with a licensed plumber right away.

Materials Needed:

  • Duct tape
  • Plunger
  • Ladder
  • Garden hose
  • Sewer auger
  • Adjustable pliers
  • Air-admittance valve
  • Mask

Climb to the roof and inspect the primary vent stack opening. It could be blocked by detritus or foliage. Clean the screen and remove any clutter.

Use a garden hose to spray water down the vent pipe. If there’s a blockage deep within the pipes, the water might dislodge it. The presence of water backing up out of the vent signals a blockage. Typically, you can address this blockage using a sewer auger, readily available for rental at most outlets.

Insert the auger into the vent opening and rotate it until encountering resistance. Turn the handle to maneuver the auger head through the blockage. Periodically retract the head to remove any debris. Once you believe the blockage is cleared, test by spraying more water into the vent to ensure it doesn’t back up.

Why Does My Sink Gurgle When I Flush the Toilet?

3. Faulty P-Trap

A P-trap is a crucial component of plumbing that forms a curved or “P” shaped pipe section. It’s typically found beneath sinks, showers, and tubs. This curved design holds a small amount of water after each use, creating a seal that prevents sewer gases from entering the building through the drain.

The P-trap’s design allows water to remain in the curve, blocking the passage of gases and providing a barrier between the indoor space and the sewage system. Its presence ensures proper ventilation and protects the occupants from potential health hazards associated with sewer gases.

If there’s damage to the trap, it might let sewer gases out through drains, leading to a gurgling noise when flushing the toilet. Also, if debris clogs the P trap, it can stop wastewater from draining, causing a similar gurgling sound.

The P-Trap has to be cleaned in order to help get rid of any debris that could be the source of the gurgling noise. Before unscrewing and taking the trap out of the pipe system, switch off all water sources. Once removed, check and clear out any dirt or buildup that may have accumulated. After you’ve made sure there are no blockages, reconnect the trap and give the sink or toilet another test to confirm the problem has been fixed.

If the P trap is broken, then it needs replacing. If the trap is concealed behind a wall, it’s best to seek a professional’s help before attempting any drywall cutting.

4. Clogged Sewer Line

Along with other plumbing issues, a gurgling sink can also be caused by a clogged sewage line. Even if the drain pipes are not linked to the septic tank, a blocked sewer line might still result in a water backup in the toilet bowl or other drain pipes.

All of your waste is transported to the septic tank or city sewer by the main sewage line. There are several items that might clog your sewer line, such as flushable wipes, liquid fat that can solidify within the pipes, and tree roots growing inside the sewer pipes.

It’s also possible for the sewer pipes to age and lose their integrity. Additionally, soil movement could result in pipe damage. The use of sulfuric acid-containing drain cleaners will also erode the pipes as well. Lastly, a toy flushed down the toilet might clog the sewage system.

Hiring a licensed plumber to clean your sewage pipes is the best course of action. Sewer line clearing may be done efficiently and swiftly by plumbers thanks to their equipment and knowledge.

It is important to get the tank emptied and cleaned on a regular basis if you own one. Gurgling sounds and other plumbing issues might result from an incorrectly managed septic system.

Final Thoughts on Sink Gurgling When Toilet is Flushed

In conclusion, the gurgling sound from your sink when flushing the toilet is typically indicative of an underlying plumbing issue. Understanding the potential causes, from blocked vents to drainage pipe problems or faulty plumbing design, empowers homeowners to take proactive steps in resolving these concerns.

Regular maintenance, periodic inspections, and seeking professional assistance when needed are vital in ensuring a healthy and functional plumbing system. By addressing these issues promptly, you not only eliminate gurgling sounds but also prevent potential water damage and maintain the overall integrity of their plumbing infrastructure.

Remember, when in doubt, consulting a licensed plumber is often the best course of action to tackle these plumbing mysteries and keep your home’s plumbing system running smoothly.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.