what happens if you leave drano in too long
Kristina Davis

Have you ever wondered what happens if you leave Drano in too long?

Would it be more effective the longer it stays in your drains, or would it impose some type of danger?

Being the “DIY person” type of individual, I decided to dig the truth behind Drano and your pipes.

I’m going to give you relevant information about leaving it inside your pipes and drains overnight, as well as how it can affect it.

Leaving Drano inside your metal or plastic pipes can damage them because it is corrosive if the stubborn dirt and scum aren’t thick enough to require its contents.

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You can leave Drano overnight but only if you do it occasionally, refrain from using it regularly.

Can I Leave Drano Overnight?

leave drano overnight

Yes and no – let me explain.

Drano is a caustic and corrosive product. What this means is that it is comprised of powerful acids that can damage metal pipes – especially plastic ones.

Yes, you can leave Drano in your pipes for hours, but only if you’re sure that the clog or the blockage is massive.

These would be the instances where the flow of water down the sink and outlets is too slow to the extent that you have to literally watch it for 5 minutes to flow down.

And no, you can’t leave it overnight if the problem is just mild because the product will directly get to the pipes and can damage them irreversibly.

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How Long Can You Leave Drano In?

how long can leave drano

As per the company’s standards, you only need to leave Drano for about 15 to 30 minutes; you have to flush it with hot water afterward.

But, as we all know, it doesn’t always work that way.

In fact, in my experience, I had to leave it for about 3 hours because of a medium-level problem with my toilet.

I tried doing the 15 to 30-minute timeframe on my kitchen sink and it worked pretty fine.

The typical timeframe of leaving Drano in your pipes is 15 to 30 minutes for minor or initial problems.

However, if the debris and stuck-up and stubborn dirt are thick and coarse, you can leave them for hours on end – you can even leave the solution overnight.

What Happens If You Leave Drano In Too Long?

what will happen

One of 2 things will happen: it will work like magic and eradicate stubborn and stuck-up dirt, or it can damage your pipes.

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If the dirt has been lingering in your piping system for a long time already, leaving Drano will be efficient and effective.

This is because it will not only soften and loosen up the dirt but will also flush it down the bottom of the system.

For a long time now, I’ve used Drano every once in a while whenever I experience slowness and dullness in the flow of water through my pipes.

In a typical sense, I use Drano once every 6 to 8 months because minor problems are solvable using a hot water flush.

What Can Drano Damage?

what can damage

On the contrary, if you leave Drano in your pipes for a long time with minimal dirt and debris, it will damage it.

To add to that, regularly using Drano is not good or healthy for your pipes.

Expect the following damages when you leave this harsh solution in your piping system without coarse debris and dirt stuck on the inner lining.

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P-traps are the pipes that are usually seen under the sink.

The purpose of their shape is to be able to filter methane and other types of hazardous gases to work their way into your homes.

You won’t usually need Drano in P-traps unless the buildup of food and grease is too much.

Toilet and Toilet Pipes

toilet pipes

Another thing that Drano can damage is toilet pipes, as well as toilet bowls.

The harsh effects of Drano can be too much for low-quality ceramic, and therefore, it can make them crack.

The heat that Drano generates can react with porcelain and make the entire structure crack.

NOTE: One thing to note in your toilets is if the drainpipe contains a wax ring. If it has, refrain from using Drano or any other liquid solution because it can distort it.

Metal Pipes

a metal pipes

Last, and most definitely not least are metal pipes. I know what you’re thinking – how come they’re damaged if they’re made from metal?

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Drano, as well as other types of liquid solutions, contain caustic soda, which can damage even metal.

Luckily, Drano only has a minimal amount of caustic soda as proven by its pH levels.

These are the things that Drano can damage, especially if they’re not used in accordance with thick debris and stubborn dirt.

Remember that, in using Drano and leaving it for a long time, the clog or the blockage needs to be thick or large.

Normal food, starch, or thin dirt buildup are things that you can flush out with about 1.5 liters of hot water.

How Do You Use Drano to Unclog Your Pipes?

use drano to unclog pipes

Here’s a brief breakdown of how you can utilize Drano to clear out and unclog your pipes.

Step #1: Clear Out Any Standing Water

The first thing you want to do is to clear out still or standing water.

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NEVER use Drano on still water because good bacteria are found to be here.

Then, if you pour Drano down on still water, it can break this organic material. Overall, the entire drainage system will be hurt.

You can wait for the water to flow down the end of the piping system before you pour Drano in.

If it’s not moving, you’ll need to suck up the water out of the drain. 

Step #2: Pour Drano In

pour a drano in

When it’s clear, the next thing you want to do is to pour the Drano solution into the drain.

Pour it directly into the hole and wiggle it so that the sides or inner lining of the pipe gets it, too.

Step #3: Let it Do Its Magic

After that, the next step is to just let Drano do its magic.

For minor drainage clogs and blockages, a minimum of 20 minutes and a maximum of 40 minutes would be enough.

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For heavier drainage problems, leaving it overnight is good.

Step #4: Flush With Hot Water

When the Drano has pushed its effects, the last and final step is to flush your drains with hot water.

Hot boiling water is what I would recommend because it can back the dissolving of stubborn dirt and it can flush out what’s left.

That’s how you use Drano to unclog your pipes without doing a lot of work! No snaking and no need to contact your local plumber!

Can Drano Worsen the Clog If It’s Left Overnight?

worsen the clog

The effects of leaving Drano overnight depend on the condition of your pipes.

For instance, if the culprit of the clog or blockage is thin such as starch, food remains, and even wet wipes,

Leaving Drano overnight can worsen it because the solution can melt the clog in under an hour and will go straight to the walls of the pipes.

On the other hand, if the buildup is thick such as grease or plastic, or if it is deep down the drain, then leaving Drano overnight will be more advantageous.

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Can Drano Cause Sicknesses and Health Issues If It’s Left Overnight?

can drano cause health issue

You might also be wondering, can Drano cause health issues if it’s left overnight?

Ideally speaking, no, it wouldn’t have adverse effects on the health of the people who are in the residence.

Drano is a product that has only a minimal level of bleach, as well as caustic soda.

More so, it won’t be inhaled by the people if it’s directly poured into the sink.

The Bottom Line

So, what happens if you leave Drano in too long? If the stubborn dirt is too thick, it’s all good.

However, if the issue is minor, it can be dangerous for the status or condition of your pipes.