Why Is My Kitchen Sink Gurgling When I Flush The Toilet?

Why Does the Kitchen Sink Gurgle When the Toilet Is Flushed?

stainless steel kitchen sink

A gurgling sink might not seem like a major issue at first, but if it persists, you may have a serious problem on your hands. This could be a sign of a larger drain or sewer problem. The expert plumbers at Mac 5 Services in Melbourne, FL, get many calls about gurgling sinks and how to fix them.

Use this guide to help you diagnose your plumbing issue. If your sinks gurgle when a toilet is flushed, call a professional plumber to inspect the issue and complete the necessary repairs.

If you live in Melbourne or Rockledge, FL, contact Mac 5 Services for all your plumbing and drain problems. We’re available 24/7 to take your call.

Key Points in This Article

How Does Flushing the Toilet Affect the Kitchen Sink?

Your main sewer line carries sewer gases produced by toilet flushes and water going down your plumbing system, which creates negative air pressure. Vent pipes release negative air pressure and prevent sewer gas from building up.

You can hear a gurgling noise in your sink when your sewer pipe is completely blocked by too much air pressure or not enough. You must keep up with routine checkups and maintenance cleaning to ensure your drain line and vent pipe continue to work in conjunction properly.

Why Does the Kitchen Sink Gurgle After Flushing?

Drain pipes and lines require sufficient ventilation to aid water flow, and a vent pipe attachment ensures that. Water slows down and gets stuck without a vent pipe to provide sufficient airflow.

A vent pipe with faulty components like a stalling valve can hinder the necessary release of negative air pressure and possibly be the cause of your gurgling sink.

The Cause Behind a Gurgling Sink

The answer is simple and can be caused by any one of these three things:

  • Sewer lines aren’t properly vented
  • A blocked vent system
  • Negative pressure built up

Each cause is easily correctable with proper tools and techniques. While you can attempt to remedy them yourself, we suggest you call a professional plumber, especially when dealing with your septic tank. You wouldn’t want to expose yourself to the toxic fumes in your septic system.

Poorly Maintained Sewer Lines & Drains Cause More Problems

Filthy piping isn’t allowing fresh air into your plumbing systems, posing major hazards. A partially blocked drain with built-up negative pressure lifts toxic fumes back up the drains, which causes the sink to make gurgling noises.

However, it continues to release fumes long after the drain gurgles. All that filth attaches to moisture and generates different contaminants that may evaporate into your home.

Don’t forget, while drain conveyances are inside your home and sewer lines are outside, they’re connected to a single pipe at the end. They all lead to a singular plumbing system, which is why a toilet flushed, a running shower, and a draining sink all end up together and affect each other.

How Your Plumbing System Works With Your Sewer

Your plumbing lines are made of iron or plastic (PVC) pipes that facilitate proper ventilation and draining water.

All pipes work in conjunction with each other and prevent sewer gas and sewage from draining slower. A blocked sewer line prevents toxic fumes and hazardous drain water from being disposed of properly.

However, most of us focus on drains and not enough on the P Trap or another plumbing fixture that plays a major role in accommodating water flow.

Vent Pipe

All sewer pipes are linked to a vent stack that provides the necessary airflow. A blocked drain may be the problem but may also stem from an underlying issue involving the three major components of your main vent pipe:

  • Main vent stack 
  • Vent opening
  • Air admittance valve

Sewer gases from our wastes circulate in our drainage systems, and venting components help expel them properly. Insufficient ventilation causes drains to pull air from the P Trap instead of the vent stacks, causing gurgling sounds.

Air Admittance Valve

A cheater valve is also known as an air admittance valve. It’s a gravity-operated device installed in the sink P Trap that acts as a water seal to catch small objects and keep them from falling down the sink drain and prevents gases like methane from coming up.

Still, as a water seal, it can’t prevent methane and other hazardous gases from coming back into your living space when the moisture built up within collects gaseous particles and evaporates. Drains that aren’t exposed to running water are prone to building up and releasing toxic fumes.

However, it’s preventable by turning the faucet on every few days. Running water should wash down any moisture and the gases it collects over time.

A completely blocked drain will drain slowly, which may cause more water for toxic particles to attach themselves to and compound the risks of toxic evaporation. If you smell sewage around the kitchen area, you need to call a professional plumber.

Do I Need To Fix My Gurgling Sink Immediately?

You won’t resolve the issue by letting your drain stay blocked, with toxic water stagnating in your pipelines.

Every time you dismiss a gurgling sink caused by toilet flushes, you risk the integrity of your P Trap. Over time it will deteriorate and fail to keep your family safe from inhaling toxic fumes. Would you want to smell your septic tank every day? That’s not only a disgusting nuisance but a hazardous one.

Should I Look Into My Sewer Lines?

Remember, a gurgling sink every time a toilet is flushed can indicate problems with your sewer line.

Problems may include a small or huge blockage, but a sink gurgles more due to improper ventilation. You don’t need to use a sewer auger to examine your pipes immediately. Instead, it would help if you looked into your sink drain, precisely your P Trap.

What Should I Do When the Sink Gurgles?

First, check your cheater valve connected to a horizontal arm on your P Trap. If the air admittance valve installed shows visible signs of wear and tear or breakages, replace it immediately to allow proper airflow back into your draining system. Sometimes, during the initial building, a contractor cuts back on costs and uses cheaper alternatives.

A cheater valve falls on their list of cost-cutting materials. It’s hidden and lesser-known, so homeowners are less likely to double-check it during a final inspection. If you smell odors from your kitchen sink, you should check under your sink first before prying open any drains and sewers.

If that doesn’t solve your problem, the second thing you should do is climb into the roof main vent stack. While replacing or patching up a faulty cheater valve requires a few tools and duct tape, cleaning out a vent stack, especially one on your roof, requires more tools, a ladder, and courage.

Climbing your roof can be intimidating. If you fear heights, call a professional, but if you can do it yourself, grab the garden hose and get up there.

How To Clean Vent Stacks on Your Roof

Clean out rooftop vent stacks by:

  • Opening or uncovering the stack.
  • Holding your hand over the opening.
  • Having someone flush the toilet.
  • Feeling for a suction (if there is one). If there is none or weak, proceed to the next step.
  • Using a sewer auger to push and prod around the vent. Do your best to really get in there to shake off and dislodge any blockages.
  • Using a garden hose to flush down loose debris.
  • Having them flush the toilet again.

You should be able to feel a suction now, or its presence should be stronger when the toilet is flushed. If you still can’t feel one, you need a professional to check on your drain lines and sewer pipes.

How To Clean the Kitchen Sink Drain

Before climbing onto your roof, you can also resolve the gurgling sound without testing your phobia of heights.

Sometimes, regularly cleaning your kitchen’s drain pipes is enough to prevent the gurgling sound. There may be an obstruction there that affects your pipes’ overall ventilation.

Non-Hazardous Drain Cleaners

Here’s an easy and inexpensive remedy you can try at home. The good news is that you might already have all the ingredients for this non-toxic yet effective drain cleaner.

  • Run warm or hot water down the drain.
  • Add 1/2 cup of baking soda. We mean baking soda and not baking powder.
  • Add 1 cup of distilled white vinegar. We haven’t tried this with other kinds of vinegar, but no one wants to literally throw money down the drain by using apple cider vinegar as an alternative.
  • Let the compound simmer for more than 10 minutes and less than half an hour.
  • Use a snake drain to dislodge any softened particles.
  • Run warm water down the drain again.

This should remedy any minor blockages and help lessen major ones.

Warning: Don’t use tools and materials in place of snake drains to avoid causing abrasion to your P-Trap.

When To Call a Professional Plumber

Call for expert services to save time and energy and prevent you from causing any further damage to your home’s pipework.

If you live in Melbourne, Florida, we have just the right team of professionals for you.

Who Can I Call To Solve the Gurgling Noise Coming From My Kitchen Sink?

For reliable plumbing services in Melbourne, call Mac5 Services. We deal with all things involving a drain pipe or sewer line.

Mac 5 Services’ technicians are skilled in examining and remedying issues Floridians have with their plumbing.

Mac 5 Services Is Your Go-To Plumber Along The Space Coast

Call us for any plumbing-related inspections, repairs, maintenance, and installations.

We can help you upgrade your current plumbing systems, replace weathered parts, and clean out completely or partially blocked sewer lines.

Call 321-244-7500 today to schedule services.

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