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How to Replace Seal on Toilet Outlet Pipe: The Complete Guide

Bad smell from the toilet can be one of the most frustrating issues ever. This kind of smell comes and goes. But when it comes, it spreads all over your house.

And the culprit behind this is a broken toilet seal. 

So, if you’re wondering how to replace seal on toilet outlet pipe, then you’re in the right place.

Because in this article, we’ll discuss everything from why you need to replace the seal to how you can replace it. And the best part is, we’ve divided it into 9 simple step-by-step instructions. So, why wait? Let’s start. 

Why You Need to Replace the Seal

Most people never think about their toilet seals. Well, that’s normal. Toilets should be long-lasting. Moreover, they should be the last thing you need to worry about.

However, like most things, a toilet seal can break. So, if you come across any of these reasons, chances are you need to replace the seal on your toilet. It’s not a simple problem like a crack on some doors. So, you better acknowledge the consequences of a broken seal on your toilet pipe. 

However, here are a few of the consequences that we’re talking about:

  1. Waste Leakage

A perfect toilet seal should prevent any kind of water or waste leakage. So, if you see any water or waste coming under the toilet, chances are you need a replacement. 

Although, this doesn’t mean only the seal is to be blamed. Any kind of leaky joint can be the reason for the leak. So, before changing the seal, do a quick inspection of the joints and other things. 

On a different note, if your house has a crawlspace or basement, check for any kind of cracks. Also, notice if the cement of the flooring is damaged or not.

  1. Wobbly Toilet

A broken seal can make a toilet wobbly. In such situations, you’ll have to replace or repair the damaged parts. And that means you’ll need to replace the seal.

Moreover, the seal can break if the bolts and nuts are too tight or loose. It doesn’t matter how little the gap is, it can cause serious damage to the seal.

That’s why never over tighten any bolt.

  1. Bad Odor

Toilet seals are airtight, preventing any kind of sewer gas from entering your house. When there’s a leak it’ll smell rotten eggs. 

This smell comes from hydrogen sulfide, a gas harmful to your health. And when you smell something like this, it means you have to change your toilet seal. 

9 Steps of How to Replace Seal on Toilet Outlet Pipe

Changing the seal on a toilet is a great DIY project. It doesn’t require any special skills. And most importantly, you can do it in about half an hour. So, let’s see how you can do it.

Tools and Materials

Step 1: Switch Off the Water Supply

The first thing you’ll need to do when your toilet seal is broken is, switch off the water supply. Usually, there’s a valve to control the water supply right under the tank. 

Although, you can also do it by cutting off supply from the main source.

After that, use the flush to get rid of the water in the tank. Lastly, you can use a shop vacuum or a sponge to drain the water in the bowl.

Step 2: Detach the Tank Hose

Now that you’ve stopped the water supply, it’s time to detach the hose. This hose is used for connecting the bowl to the tank. 

There might be some water in the hose, so it’s a good idea to put a bucket under it. 

As most people don’t need to repair their toilet that often, the bolts might look old and rusty. In such cases, applying some penetrating oil will work. 

Now, wait for 2-3 minutes and try loosening the bolts. 

Step 3: Remove the Bolts

You’ll need some space to work, also the toilet might be too heavy for carrying. For this, you need to remove the bolts attaching the tank and the bowl. By removing those, you’ll be able to move those separately. 

However, make sure to put  4 blocks in a corner of the room. You should place the blocks before starting out. You see, these blocks will keep the toilet drain undamaged. 

A piece of quick advice, try placing the blocks at a little angle. By doing this, you’ll prevent the toilet from falling over.

Step 4: Take Out the Toilet Bowl

First, put down the toilet seat. Now, pick up the bowl, keeping it parallel to your floor. Also, make sure that the existing toilet doesn’t come out of its place. 

Now, put down the toilet on the blocks that you’ve previously placed. 

Step 5: Pull Out the Wax Ring

Before starting, put on some disposable gloves. Also, keep the room well-ventilated as this kind of project can get messy. 

First, using a putty knife, remove the ring. Then, use a clean cloth dipped with mineral spirits to clean out the anchor flange and the drain.

Now, remove the old mounting bolts and inspect to see if there are any damages. Keep the drain blocked with a large towel or rag to prevent things from falling into it.

Moreover, it’ll also keep out any kind of bad smell from spreading around the house. 

Step 6: Replace the Wax Seal

First of all, unscrew all the bolts on the toilet anchor flange. Then, check the flange to see if there are any cracks or if it’s missing any parts. Also, fix any kind of problem before any new mounting bolts.

Now, put your disposable gloves on and add the new wax seal to the toilet outlet pipe. Although, be gentle about placing the wax seal as pushing it too hard can put it out of shape.

Step 7: Connect the Toilet

Now, pick up the toilet that you’ve removed and put it in its rightful place. Although, remember to put the toilet in the exact previous position as you’ll need to reconnect the mounting bolts. 

Lastly, move it gently until it has a tight seal with the seal under it.

Step 8: Tighten the Bolts and Nuts

After the toilet is perfectly in its place, it’s time to tighten the nuts and bolts. First, attach the washers and nuts on them, and tighten them. 

However, never over tighten any nuts or bolts as too much pressure can break these things. 

Finally, attach the decorative caps on the bolts. These caps do a good job of making the toilet safe. Moreover, they also make it look great. 

Step 9: Connect the Pipe

Put on some new thread tape on the tank before you connect it. Then, turn on the water supply and keep an eye out for any leakage for about an hour. 

Lastly, check again the next to see if the seal is working properly. If not, you’ll have to apply it again.

That’s it. You’re done.


So, that’s all we have to say. By now you should know how to replace seal on toilet pipe. Although, if your toilet is still leaking somehow, you should call a trained professional. 

Before wrapping up, we have a simple tip for you. Whenever you remove your toilet, make sure to replace the seal. It’ll keep your toilet in good condition. 

Good luck!