Why Is My Toilet Gurgling When The Washer Drains? Causes and Solutions

If your toilet starts bubbling and gurgling every time you run the washing machine, it can be alarming and frustrating. However, there are a few common reasons why this annoying problem occurs.

The good news is, in most cases, toilet gurgling during washer drainage can be fixed with some simple DIY solutions. Understanding what causes the issue is the first step towards resolving it.

What Causes Toilet Gurgling During Washer Drain?

There are a several factors that can lead to gurgling noises coming from your toilet when the washing machine drains:

Drain Pipes Are Connected

Most household drain pipes are all connected. This means the washing machine outlet drain pipe is linked to the main sewer line that your toilet also drains into. When the washer pumps water out to drain, it creates pressure that forces air back up the pipes. This air bubbles up through the toilet bowl, creating a gurgling sound.

Negative Air Pressure

As the washing machine drain empties out water, it leaves space in the pipes. This creates a suction effect that essentially sucks air down through the toilet drain to fill the void. The suction results in gurgling as air bubbles through the water.

Blocked Vent Pipe

Vent pipes are installed alongside drain lines specifically to release air. However, if the vent pipe gets clogged with debris, air can't escape as it should. The buildup of excessive air pressure then gets pushed through the toilet, causing bubbles and gurgling.

Partial Clog or Blockage

Even a small clog or blockage in your drain lines or trap can restrict proper airflow and cause problems. With obstructed airflow, air has no choice but to escape through the toilet bowl, resulting in bubbling and gurgling.

Improperly Installed Drain

If the washing machine drain line was installed improperly, it may allow too much air to get forced through the pipes when the washer pumps out water. This rapid airflow results in air bubbles that gurgle up through the toilet.

Excessive Water Usage

Using large amounts of water in a short time can overload drain pipes. The pressure of excessive water going down the drains forces trapped air to bubble up through the toilet, causing gurgling noises.

Low Water Pressure

Low home water pressure allows air pockets to accumulate in the drain lines. These air pockets then get pushed through the toilet when the washing machine drains, making gurgling sounds.

High Water Table

In areas with a high groundwater table, water can seep into drain pipes. This displaces air already inside, which then bubbles up through the toilet bowl and causes gurgling.

Tree Roots

Over time, tree roots can grow into drain pipes, obstructing air flow. When the washer drain pushes air through clogged pipes, it causes disturbances that make gurgling sounds in the toilet.

How to Fix Toilet Gurgling When the Washer Drains

Now that you know what's causing the gurgling, here are some solutions to fix this annoying problem:

Install a P-Trap

A P-trap holds water in the drain pipe to prevent air passage. Installing one on the washer outlet will block air from bubbling up from the drain back into the toilet.

Clear Clogs and Blockages

Use a drain snake or auger to remove any obstructions in your drain lines and trap. Eliminating clogs allows air to flow freely again without getting forced up through the toilet.

Unblock Vent Pipe

Remove any debris like leaves or nests from your vent pipe so that air can escape outside as it should. Proper venting prevents excessive air pressure from building up.

Fix Improper Drain Installation

If the washing machine drain line was installed incorrectly, it may need to be re-installed according to code. This will prevent excessive air from getting forced through the pipes during drainage.

Adjust Water Usage

Avoid running multiple washing machines simultaneously if possible. Spread out laundry cycles throughout the day instead. Also, use a high-efficiency machine that consumes less water volume.

Increase Water Pressure

Consult with a plumber about safely increasing your home's water pressure if needed. This minimizes air pockets from forming inside the drain pipes.

Install Sump Pump

In areas with a high water table, a sump pump can drain away groundwater before it enters your pipes. This prevents water displacement of air.

Clear Tree Roots

You can attempt using a mechanical pipe rooter to remove roots growing into your drain line. Eliminating obstructions allows air to flow freely without gurgling up through the toilet.

When to Call a Professional Plumber

If trying the DIY solutions doesn't solve the gurgling issue, it's best to call a professional plumber. They have the expertise and tools to fully diagnose and repair the problem. It's also smart to call a plumber for major drain line damage or if improper installation is suspected. If foul sewer gases start entering your bathroom along with gurgling, this indicates a larger problem requiring immediate professional help.

Finding the source of washing machine drainage causing your toilet to gurgle isn't too hard with some basic plumbing knowledge. In many cases, the problem stems from connected drains and is fixable with some simple adjustments and unclogging. However, if DIY solutions don't do the trick, expert help may be needed. Persistent gurgling or sewer gas smells should never be ignored, as they can signify larger issues. Addressing problems promptly prevents further plumbing damage down the road.