What Happens If You Leave Liquid Plumber In A Drain Too Long?

Nick Durante
by Nick Durante
Liquid Plumber is a powerful cleaning chemical that does its job well but is also quite risky. That is because it can damage the drain and cause corrosion after an extremely short time. Follow along as we explore how long it takes for Liquid Plumber to damage your drain.

Pipes and drains can clog easily whether it be soap scum, food residue, or hair that won’t wash down. It’s natural to opt for a cleaning product like Liquid Plumr (Plumber) and Drano for ease of use and convenience. However, these chemicals are caustic, so what happens if you leave Liquid Plumber in for too long?

Liquid Plumber can corrode and damage your pipes if you leave them in for too long because it’s caustic. Both plastic and metal pipes are susceptible to damage when using drain cleaners such as Liquid Plumber. You should only let the Liquid Plumber sit in the drain for 15 minutes before you wash it away with water.

Liquid Plumr, or Liquid Plumber, and products like Drano are useful but potentially damaging to pipes. Leaving any chemical drain cleaner in a drain for longer than instructed can cause expensive pipe damage. Follow along as we explore what happens when you leave Liquid Plumber in a drain for too long.

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How Long Can You Leave Liquid Plumber In Drain?

You can leave Liquid Plumber in a drain for no more than 15 minutes to avoid pipe damage. It is safe to leave the drain cleaner in the drain for longer if there is slow-draining standing water that won’t go down. Brands like Liquid Plumber and Drano recommend that you wash away the remaining solution with water after the 15-minute mark.

It’s important to set a timer once you’ve poured the Liquid Plumber into the drain, disposal, or toilet. If you want to avoid potential pipe damage, you can always use a plumbing snake, wire hanger, or other mechanical methods. You can wash the Liquid Plumber down the drain before the 15 minutes are up but you may not achieve the best results.


Liquid Plumber and Drano contain caustic chemicals, and that’s why they’re able to dissolve pipe obstructions. Unfortunately, that also means that they can damage and even dissolve the pipes themselves. Plastic pipes are more susceptible to damage, but metal pipes can be corroded by Liquid Plumber and Drano as well.

Avoid using Liquid Plumber in the toilet because the plumbing is more likely to be damaged by the chemicals. It is okay to use Liquid Plumber in your drains occasionally, but daily and weekly use can quickly cause expensive plumbing damage. Old pipes in particular are much more likely to be eaten away at by the chemical drain cleaner of your choice.

If you need to use Liquid Plumber more than 3-4 times per year, you can damage your pipes and drain. Contact a plumber if your drains get clogged that frequently, as it could be a sign of more serious damage. Otherwise, you can try using flanges, plumbing snakes, plumbers, and natural enzyme solutions for clogs.

Toilet Damage

You can severely damage your toilet when you put Liquid Plumber, or similar chemicals, in it. Liquid Plumber is extremely caustic and can damage not only the pipes but also the wax ring that seals the drainpipe. Check to see if your toilet has a wax ring on the drainpipe, and if it does, you should avoid Liquid Plumber.

Liquid Plumber and similar products can damage the wax ring and eat away at it until it’s ineffective. This can lead to future water damage as water will leak from the wax ring each time that you flush the toilet. The chemicals also eat away at pipes which can be even more destructive with toilets than say, a sink.

Your best bet with a clogged toilet is a classic plunger or plumbing snake, and not chemicals. A slow flushing toilet can be cleaned by Drano and Liquid plumber, but enzyme cleaners often work better. Consider using Liquid Plumber or Drano as a last resort instead of your go-to for unclogging a pipe or drain.

Pipe Damage

Drain cleaning chemicals are bad for pipes whether they’re made of metal and plastic and should be used sparingly. Liquid Plumr, or Liquid Plumber, is effective at unclogging drains, but the mix of bleach and sodium hydroxide makes it a caustic product. If you recently used a cleaning product that contains hydrochloric acid, the Liquid Plumber can create an adverse reaction in the pipes.

This reaction leads to gaseous chlorine being created within the pipes which can damage them severely. Liquid Plumber is most effective for basic clogs caused by resin buildups and soap scum in the drain or pipes. Large clogs often require a mechanical method, such as a plumbing snake, so the damaging chemicals aren’t often worth it.

Sure, drain cleaning chemicals can get rid of obstructions, but they can easily eat away at your pipes. It’s no wonder that plumbers often decry drain cleaning chemicals because it creates nasty damage. Sometimes, cleaning chemicals can make clogs worse because they can cause blockages to solidify even further, and you’ll still have damage.

Risks Of Using Drano To Unclog A Drain

Can I Pour Liquid Plumber In Standing Water?

Yes, you can pour Liquid Plumber in standing water, but it’s not the best option for unclogging the drain. This brand, and others like Drano, say that the chemical is designed to be effective in standing water. With that said, standing water often drains very slowly with clogged pipes, and that means the chemical sits longer.

Liquid Plumber states that it’s okay to leave the chemical in for longer than 15 minutes when there is standing water. That can easily raise a red flag if you’re concerned about the caustic properties of Liquid Plumber. You certainly can use Liquid Plumber in standing water, but your best option would be a plumbing snake.

Related Questions

Does Liquid Plumber dissolve hair?

According to Liquid Plumr, yes, it does dissolve clogs that are caused by a buildup of hair. You can also dissolve hair in a drain by using a mixture of vinegar and baking soda, and that’s safer for pipes. Otherwise, you can pour Liquid Plumr and allow it to sit for 15 minutes before washing it down with water.

Can Liquid Plumber make a clog worse?

Liquid Plumber and similar products can sometimes make a clog worse if the obstruction becomes more solid. Acidic chemical cleaners are quite strong and can sometimes work against you in congealing the blockage. If the drain is completely blocked, it is more effective to use a snake, plunger, or wire hanger than a chemical product.

Is Liquid Plumber Dangerous?

Liquid Plumber and dangerous is dangerous if you get it in or around your eyes, leading to possible permanent damage. Avoid inhaling Drano or Liquid Plumber at all costs as it contains sodium hydroxide which is dangerous. Chemical cleaners can also be dangerous when they come into contact with your skin, so it’s best to wear gloves.

Should you use Liquid Plumr?

You should only use Liquid Plumr if the clog is minor and you haven’t used it in several months. Chemical cleaners often won’t affect if the clog is large, so the chemicals can only harm. Clogs caused by residue from food or soap scum are the ideal use for chemical drain cleaners, and larger clogs require a snake.

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Summing It Up

You can severely damage your pipes if you leave Liquid Plumber in for too long. The chemicals inside of it are caustic and can corrode metal and plastic pipes easily. Continual use, more than 3-4 times per year, increases the risk of corroding and damaging your pipes.

If your toilet is clogged or the water level recedes after flushing, avoid using Liquid Plumber. A liquid Plumber can be used for toilets, but it can also erode the wax ring on the drainpipe. Instead, you should use a plunger, natural enzyme cleaner, mineral deposit remover, or a plumbing snake to unclog it.

Leave Liquid Plumber in the drain for no longer than 15 minutes and spray it with water afterward. This will minimize the risk of pipe damage, and will also limit the amount of time you have to breathe it in. Liquid Plumber is a great product, but it’s important to use it sparingly to avoid pipe damage.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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