We’ve all heard it before.
That peculiar sound of gurgling coming from the toilet when the washing machine drains.
It’s one of those sounds that you can’t seem to ignore and it’s certainly not the most pleasant sound to hear.
So why does it happen?
The Science Behind It
The answer lies in the science of plumbing.
Toilet gurgling happens because of a phenomenon called backflow prevention.
In order to understand why the toilet gurgles when the washer drains it helps to first understand what backflow prevention is.
Backflow prevention is a mechanism that prevents contaminated water from entering the main water supply.
This is done by having a one-way valve that prevents contaminated water from flowing back into the water line protecting the water supply from being contaminated.
The problem is that when the washer drains the water pressure in the drain can push the contaminated water from the washing machine past the backflow prevention valve.
This causes the contaminated water to enter the main water supply and since the water pressure in the main line is lower than in the drain the contaminated water is forced back up the drainpipe and into the toilet resulting in the dreaded gurgling sound.
The reason why your toilet gurgles when your washer drains is because of the plumbing in your home.
When water is drained from your washer it travels through the same pipes as the water that’s in your toilet.
As the washer water rushes through the pipes it creates a vacuum effect that causes the water in your toilet to be sucked out resulting in a gurgling sound.
How To Stop It
Fortunately there are ways to prevent this from happening.
The best way to prevent backflow is to install a water hammer arrestor which is a device designed to absorb the shock of sudden pressure changes in the plumbing system.
This can help prevent the water pressure in the drain from pushing the contaminated water back up the pipe and into the toilet.
In addition you can also install a backflow prevention valve in the main water line.
This valve won’t prevent the contaminated water from entering the main line but it will keep it from flowing back up the pipe and into the toilet.
One of the easiest ways to do this is to install a backflow prevention valve.
This valve will help to prevent the water from flowing backwards in the pipes so the toilet gurgling won’t occur.
Another simple solution is to make sure that the washer water is draining slowly.
If the water is draining too quickly it can create a vacuum effect that causes the toilet to gurgle.
To prevent this you can use a drain hose that is longer or you can add a few inches of water to the washer before draining it.
Why Is This Important?
It’s important to understand why your toilet gurgles when your washer drains because it can be a sign of a bigger issue.
If the water is flowing back into your toilet it could be a sign that there is a clog in your pipes.
If this is the case you should call a plumber right away to have them take a look at the problem.
Conclusion
Understanding why your toilet gurgles when your washer drains is the first step to being able to prevent it.
With a little bit of knowledge and the right tools you can stop the gurgling and enjoy the peace and quiet that comes with a functioning plumbing system.