Check Out How To Remove Cast Iron Toilet Flange

Fixing issues with toilets can be time-consuming and tiring. Anyway, that’s what this post seeks to simplify.

The toilet flange connects the waste pipe to the toilet above it. You can get it in materials like PVC or aluminum. Cast iron ones are seen in some older homes.

Toilet flanges can break or crack over time. And that can lead to leakages or cause the toilet to rock. As such, you’ll have to remove and replace the flange to fix the problem.

This article gives you guidelines on how to remove cast iron toilet flange. You’ll also learn how to replace it.

How To Remove Cast Iron Toilet Flange

Follow these steps to take off the cast iron toilet flange without causing any further damage to the unit.

Step#1: Remove the toilet

Before you can take out the flange, you have to remove the toilet. To do this, turn off the valve to disconnect the water supply to the unit. You’ll find the knob behind it.

Next, remove the lid from the tank. Then, press down the lever to flush the toilet several times. Ensure the water tank is empty or drains as much as possible.

After that, unscrew the ball floating inside the tank. Then, take off the hose that supplies water to the toilet. You can disconnect it with adjustable pliers if it’s too tight.

An open container or towel will come in handy to collect any leaks that may occur. Then, use a large sponge to absorb the remaining water in the tank and bowl.

Loosen the nuts at both sides and the center of the tank. They attach it to the bowl. You can do this with a wrench. Now, lift the tank from the bowl and keep it safely away from the work area.

Next, place some old newspapers or towels on the bathroom floor. Then, loosen the nuts below the bowl at both sides of the toilet base. If there are plastic caps on them, pull them off. If the nuts are rusted and stuck, you can cut through the bolts with a close-quarter hacksaw.

Now, break the wax seal that connects the toilet to the flange. You can hit the sides to do this or rock the bowl back and forth.

After that, lift the toilet. You may need to get someone to help you out, as it’s usually heavy. If you can carry it alone, support the weight with your legs, not your back. Lift it straight up so the bolt can come off quickly.

Then, place the toilet on the old newspapers or towels on the bathroom floor. Use a towel to clean up any leaks.

Step#2: Block the waste pipe

After you remove the toilet, you want to block the waste pipe. It’ll prevent unpleasant odor from sewer gases.

Please don’t wait till after removing the flange before you do this. That’s because it’s best to stop the odor earlier. It’ll also prevent things like bolts or screws from going down the pipe.

You can block the pipe with an old towel or t-shirt. Ensure you don’t push it down too tight or far. So, you can easily remove it later.

Step#3: Clean and check the flange

You have to clean and check the flange to know the best way to remove it. You’ll notice a wax ring on top of the flange. It seals the toilet base, and flange connection. Thus, it should look discolored. But use a putty knife to scrape it off.

An old towel or newspaper will come in handy to wipe the putty knife as wax sticks to it.

Step#4: Remove the bolts

Before you remove the toilet flange, you have to remove the bolts. You can use a socket wrench to do that. Make sure you loosen each one a little per time. That’ll ensure the flange won’t crack at the pipe connection.

Most modern versions have screws, so you’ll need a screwdriver to unscrew them.

You may need to use a chisel and hammer to remove the flange if it’s badly corroded. Cast iron can easily break when you use a chisel on it. So be careful when you do that, as the pipe may also be cast iron. If it damages in the process, you’ll have a bigger problem to handle.

Step#5: Test the flange

The next thing to do is to test the flange. Use a pry bar to do it. The aim is to check if it’s already loose. That’ll enable you to determine what to do next. Check if it cracked down to the stem. If it is, you can easily pull it off. If not, you’ll have to break it off.

If the flange doesn’t have a crack, you’ll need to do that yourself. Use a cold chisel and a hammer.

First, lay the cold chisel on the flat part of the flange that lies on the floor. Ensure it points to the outside edge. That’s because any impact on the inner edge can crack the connecting pipe. Now hit the chisel with a hammer till the flange cracks.

Step#6: Remove the flange

After that, you have to remove the flange. To do that, insert a pry bar under the edge to push it up. That should remove it.

However, if it comes up a little, use a piece of wood as a shim to hold up that part. Then use the pry bar to push up another section of the flange. Do this continuously until it’s free. Then pull it out.

Finally, vacuum the dust or debris around the pipe and bathroom floor.

How To Replace A Cast Iron Toilet Flange

Follow these steps to fix your new cast iron toilet flange.

Step#1: Buy the correct replacement flange

To replace the old or damaged flange, you have to buy the correct one. It’s best to get a solid fit that will sit nicely on the waste pipe and floor.

One way to do it is to take the old flange to a hardware store and purchase a good match. The new one should have the same shape and size, as identical as possible.

Another way is to measure the inner diameter of the drain pipe. Note the size and use it as a reference to buy a new one. It’s a great way to do that, especially if the old flange broke into pieces.

Buy a wax ring to go with the new flange.

Step#2: Install the flange

Now, you have to start installing the flange. First, set the bolts in it. Ensure they are on both sides of the flange. Set aside the washers and nuts for each one.

You can reuse the bolts of the old flange if there’s none in the new kit. Ensure they are still reusable.

Next, set the flange on the waste pipe. Make sure the neck fits firmly. And ensure the edges rest on the floor. You can chisel away the border of the flooring to ensure it sits well.

If it’s still not on the same level as the floor, then you’ll need to fix the bathroom flooring.

Step#3: Secure the flange

After that, secure the flange in place. Use a screwdriver to drive the screws through the flange’s edge and into the flooring. There should be existing holes in the floor where you can pass the screws. If there are none, use a drill to create new ones.

If the existing holes are too large, insert plastic wall anchors into them using a mallet. Then drive the screws through the flange and into them.

Check for any loose screws or washers around the flange or drain pipe and pick them out. Then, remove the old towel from the waste pipe. You have to remove the materials first to ensure they won’t fall into the tube when removing the rag. Ensure you dispose of it.

Now tilt up the toilet and set the wax ring in position.

The round edges of the ring should be over the pipe stub under the toilet. Don’t change its shape as you do so, but make sure it’s firm. Inserting the wax ring this way will help create a great seal around the toilet.

But you can also place the wax ring on top of the flange and set the toilet on it. If you prefer it this way, lay it rounded side up.

Step#4: Set the toilet in place

The next thing is to set the toilet in place. Ensure the holes in the toilet base fits well with the bolt that points from the flange.

When it positions correctly, press down the bowl rim at the back to change the shape of the wax ring, do it firmly. And that seals the connection.

You can do this whether you place the ring underneath the toilet or on the flange.

Next, place the plastic washers on the exposed bolts. Then put a metal one and tighten the nuts by hand. Use a socket wrench to secure them properly.

You can cover the bolts with plastic caps. But if they’re too long, trim them with a hacksaw so the caps can fit.

Step#5: Reconnect the water supply

Now it’s time to reconnect the water supply. First, connect the hose under the toilet tank. You can use a wrench or adjustable pliers for this. However, if the couplings are plastic, you can hand-tighten them.

Next, turn on the valve. Water will start running into the tank when you do so. Check for leaks as soon as the tank fills up. And then examine the connection between the toilet tank and the supply line.

After that, flush the toilet several times. Ensure there are no leaks around the base or floor area. If there is, you have to repeat the process or call a plumber.


It’s easy to remove a cast iron flange. All you have to do is safely disconnect the water supply and other related connections to the toilet. Then remove the toilet tank and bowl carefully. And you’ll see the flange to unscrew and remove it securely.

You can also replace the flange to repair the damage. However, you have to do so carefully. You can also contact a professional to do it.

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