What Happens if You Leave Liquid Plumber in Too Long?

Last Updated On June 12, 2024

Updated on November 26, 2021



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what happens if you leave liquid plumber in too long

A clogged drain can cause serious frustration, especially when it occurs on a morning when you are already running late.

Many people decide to leave Liquid Plumber or Drano in the drain longer than instructed to tackle tough clogs, thinking that the longer it sits in the pipes, the more effective it will be. 

What happens if you leave Liquid Plumber or another caustic drain cleaner in your drain for too long? Will it cause an emergency, or will you ultimately be ok?

In this PlumbingNav guide, we will cover:

  • What you need to know about leaving Liquid Plumber in for too long
  • How long should you leave Liquid Plumber in for?
  • What to do if you leave Liquid Plumber in for too long?

What's In This Guide?

      What You Need To Know About Leaving Liquid Plumber In For Too Long

      Liquid Plumber is a caustic drain cleaner, which contains sodium hydroxide or sulfuric acid. Liquid Drano Max also uses chemicals in its formula.

      These products work well on a number of different clogs, including soap scum and toilet paper. 

      While effective, these harsh chemicals can cause serious damage. 

      The hazardous fumes can also irritate the user’s skin and eyes, creating a health risk and making it wise to wear goggles and gloves when using a chemical-based drain opener. 

      Some alternative methods to clearing a stubborn clog include:

      • Drain snake
      • Boiling water
      • Natural drain cleaner
      • Homemade drain cleaner

      How Chemical Drain Cleaners Damage Plumbing

      We will cover some of the ways that chemical drain cleaners can damage your plumbing, especially when left in the drain pipe too long. 


      Corrosion refers to the natural process of metal turning to rust over time, deteriorating the metal and leading to leaks. Rust can also get into your drinking water, making it unsafe for your family to drink.

      Some older homes may still have metal pipes, so corrosion is one of the most damaging things that can happen to your plumbing system if your pipes are metal.

      If you use a liquid drain cleaner, you may unknowingly expedite the corrosion process if you have metal pipes. However, luckily, most homes use plastic pipes that don’t become susceptible to corrosion. 

      Toilet Leak/Sink Leak

      Some people use a caustic cleaner in a clogged toilet only to find that it can eat at the wax seal around the toilet bowl and create a toilet leak. 

      Similarly, if you leave a Drano product in your bathroom sink too long, it can result in new leaks that can lead to new repair bills. 

      How Long Should You Leave Liquid Plumber In For?

      In most cases, you should only keep Liquid Plumber in your drain for a maximum of 15 minutes. However, you can leave Liquid Drainer in for as long as 30 minutes if it must travel through standing water to get to the clog. 

      To compare, the best enzymatic drain cleaners recommend leaving the cleaner in the drain for 6 – 8 hours or overnight while they “eat at the clogs” and don’t pose risks to your system.

      did you know liquid plumber left in pipes too long

      What To Do If You Leave Liquid Plumber In For Too Long (6 Steps)

      If you made the mistake of leaving Liquid Plumber in your drain line for too long, that doesn’t automatically mean that you’ve ruined your plumbing system. Take these 6 steps to rectify the damage and also open your drains again. 

      Step 1: Examine the Pipes

      First, you need to examine the possible damage in the immediate area where Liquid Plumber was used. 

      If you’re lucky, you only need to worry about a little corrosion to the pipes (if you have metal pipes). However, you may also have a new leak. 

      To check for a leak, you will run water through your plumbing and check for moisture around the pipes it was used on. However, finding a leak may be difficult if you still have a clog. 

      Once you examine the damage, you need to gather your supplies and wear the correct clothing and protective gear to work on your plumbing. 

      Step 2: Remove Existing Clog

      If the chemical drain cleaner did not clear out the clog, you will need to find an alternative way to remove anything from your sink drain. 

      Some of the most common causes of a clog include:

      • Hair
      • Food waste
      • Grease
      • Oil
      • Toothpaste
      • Clay masks
      • Paint
      • Foreign objects
      • Soap
      • Paper

      While the best natural drain cleaners work quite well, if the Liquid Plumber didn’t do the trick, you will want to save the natural cleaners for plumbing maintenance or a slow drain. 

      Two of the most popular ways to remove a clog are to use a plumbing snake or disassemble the plumbing to reach the grease clog. 

      A snake is a long, malleable device that you put into your drain to reach the clog. While effective for use in the shower drain and garbage disposal, an auger won’t work if the clog is deeper than the auger can reach, such as in the septic tank.

      To disassemble your plumbing under your sink, you need to possess an intermediate amount of DIY knowledge and contain the proper tools. 

      Learn more about how to remove any item from your sink drain

      Step 3: Flush Pipes Thoroughly

      Once you remove the drain clog, you will want to remove any remaining chemicals in your plumbing system. The best way to do this is to run your hot water from every relevant fixture. Continue to let the water run for about 15 – 30 minutes.

      Step 4: Clean Corrosion (If Needed)

      If the corrosion affected exposed metal plumbing, you can wipe away some of the corrosion yourself using a mixture of white vinegar, baking soda, and salt. Apply the paste to the corrosion. After about 15 minutes, wipe the paste away. Cleaning the corrosion away will prevent it from spreading as quickly.

      Keep in mind that you may not be able to clean the corrosion off of pipes you can’t access easily. 

      Step 5: Call a Plumber 

      If you cannot remove the clog yourself or reach the corrosion, it’s time to call a plumber to get professional plumbing repair services. 

      Step 6: Prevent Clogs in the Future

      To truly resolve the issue, take steps to prevent clogs to ensure that you don’t need to use Liquid Plumber in the future. 

      Some ways to prevent clogs include:

      • Install a drain strainer
      • Avoid rinsing unsafe items down your drain
      • Perform monthly drain maintenance, such as using a drain stick

      Final Thoughts On What Happens If You Leave Liquid Plumber In Too Long

      If you leave Liquid Plumbr in for too long, it can damage your pipes. If this happens to you, take action right away! Once you repair the damage, take the proper precautions to avoid clogs in the future. 

      Also, consider using an enzymatic drain cleaner or natural drain cleaner designed to be safe for your plumbing instead of a chemical cleaner. 

      FAQs For Leaving Liquid Plumber In For Too Long

      Is it safe to leave Liquid Plumber overnight?

      No, do not leave Liquid Plumber overnight. 

      How long can you leave drain cleaner?

      A chemical drain cleaner should not sit for more than 15 minutes or 30 minutes with standing water. 

      You can leave an enzymatic drain cleaner for 6 – 8 hours. 

      Can Liquid Plumber damage pipes?

      Yes, Liquid Plumber can damage your pipes by causing corrosion if you have old, metal pipes. 

      How long do you let Liquid Plumber sit?

      You should only let Liquid Plumr sit for 15 minutes.

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      About Plumbing Navigator

      We write about "all things plumbing," helping you navigate common questions, repairs, and the best plumbing products on the market.

      About Plumbing Navigator

      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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