Simple Tips on How to Remove Plastic Nut From Toilet Tank

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Plastic locknuts hold together different parts of your toilet, including the fill valve and the water supply hose.

If you want to learn how to remove the plastic nut from your toilet tank, you only need the motivation and some good old-fashioned elbow grease.

It’s one of the simplest DIY projects in your home. 

Here are the step-by-step instructions on how to remove plastic nut from toilet tank.

6 Steps to Remove the Plastic Nut From Your Toilet

Be extra careful when removing the plastic locknut from the tank — you don’t want to crack it and see water flooding your bathroom.

Step 1: Close the Water Fill Valve

The most important thing to do is close the water fill valve that feeds into your toilet tank. You can do this by turning the handle clockwise until it stops.

If you can’t find the shut-off valve in the bathroom, you can close the main water supply to the entire home. You will likely find this valve in the basement, garage, or just outside your house.

Step 2: Place a Towel Under the Toilet Tank

When it comes to bathrooms, you can never be too safe. Even if you close the water supply hose, there may still be leaks somewhere. 

Perhaps the toilet is leaking from the tank bolts. If so, place a towel at the bottom of your toilet bowl. That way, it will be easier to clean up if excess water spills or leaks.

Step 3: Remove the Lid From the Toilet Tank

Grab your toilet tank lid and lift it, revealing everything inside your toilet tank. If it’s been a year or two since you last did it, the lid may be a bit stiff and harder to pull off.

You may need to give it a good clean before putting it back on once you’ve finished removing the nut.

Step 4: Drain Water From the Tank

Step number four is draining the water from your toilet tank. Flush the toilet, and all the water will start pouring into your toilet bowl. Repeat the process until there’s no more water in your tank.

If you are unable to remove all the water from the tank, try one of these methods:

  • Sponge and bucket: Once you cut the water supply, use a dry sponge to absorb the water and pour it into an empty bucket.
  • Use a dry towel: If you don’t have a sponge, you can use a towel instead. Try to pick up as much of the water from your plastic tank as possible before proceeding.
  • Wet/dry vacuum: If you cannot flush all the water out of the tank, use a Stanley wet/dry vacuum to remove what remains.

Step 5: Remove the Plastic Coupling From Inside the Tank

Now that you’ve removed the lid and cleared the tank, it is time to remove the plastic coupling inside. It’s an overflow tube that you can disconnect easily.

At this point, you can get rid of the last remaining remnants of water left in your tank. Do so by removing the drain stopper located at the bottom of your toilet bowl.

Step 6: Unscrew the Plastic Nut

You are now good to go — unscrew the plastic nut. All it takes is a pair of locking pliers or an adjustable wrench to hold and turn the lock nut clockwise. Just keep turning the nut until it disconnects from your toilet.

If it’s not old or worn out, you will notice how easy removing a lock nut from the toilet tank is.

PRO TIP: While trying to remove the large plastic nut from the toilet tank, make sure to do it slowly and gently. It’s a piece of plastic, and it may break if you apply too much force with the adjustable wrench.

But don’t worry if you do — you can easily buy a new plastic locknut from your local hardware store.

What to Do When the Lock Nut Is Stuck?

Sometimes a lock nut won’t twist because it’s stuck. In this case, you can try a few more solutions.

Step 1: Loosen It Using Heat and Then Try to Remove It

The first option is to use some heat to make the plastic softer. You can use a hairdryer or any other source of mild heat for this purpose. Don’t forget to apply weak pressure on the nut while you warm it up.

After heating, try gently pushing down on the locknut with pliers. If you tap lightly, it should start to loosen.

Step 2: Calcium Dissolver

In case you have calcium buildup inside your toilet tank and over the plastic nut, a calcium dissolver can help. For example, CLR PRO is a non-toxic cleaner for toilets where hard water scale buildup occurs. CLR PRO dissolves calcium and eliminates rust, allowing you to more easily remove the nut. 

You will need to wait for the chemical to dissolve the calcium for roughly 10 minutes before proceeding.

Step 3: Try WD-40 Spray

The final solution is to use WD-40. Spray the locknut until you cover it entirely, then wait for five minutes or more and clean the plastic nut using a piece of cloth. After, you can try to remove the nut again.

The disadvantage of WD-40 is its strength — the spray can sometimes damage the plastic.

Reasons to Remove Plastic Nuts From the Toilet Tank

If you wonder why it is necessary to remove plastic nuts from the toilet tank, here are some of the most important reasons:

You Need to Replace the Tank

If you want to replace the toilet tank, you must remove the plastic nut beforehand. The same goes for removing old parts and installing new ones.

You Want to Adjust the Water Flow

Sometimes you don’t like how the toilet flushes and want to adjust the water flow.

The Plastic Nut Is Leaking

If the plastic nut is leaking, the only way to fix the problem is by replacing it with a new one.

Tools to Use to Remove the Plastic Nut

Removing the locknut from the toilet tank is one of the most straightforward DIY projects, so it only requires a few tools.

All you need are pliers, Channellock adjustable wrench, a screwdriver, rubber gloves, and a new plastic nut (if necessary).

The Bottom Line

Removing the plastic nut from the toilet tank is easy if you have the right tools and follow these steps:

  • Step 1: Close the water supply line
  • Step 2: Place a towel under the toilet tank
  • Step 3: Take the lid off the top of the tank
  • Step 4: Drain the water from the tank
  • Step 5: Remove the plastic coupling
  • Step 6: Unscrew the nut by turning it clockwise

We are sure you can pull this off, so make sure to give it a try! 


Can I reuse plastic nuts?

Yes. If you don’t break the plastic nut when removing it, you can install it again. But if broken, you will need to purchase new plastic nuts for the toilet tank.

How do you loosen a plastic locking nut?

Use hot water or a hairdryer to make it warmer and looser. This will take you around five minutes to do, but be careful with your hands to avoid getting burned — you should wear rubber gloves. 

If you’re using hot water to warm it up, do it with a wet towel. The plastic will react to the heat quickly, and will become more flexible in minutes.  

When done, you can softly push down on the locknut with pliers. If you tap lightly, it should start to loosen.

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