How to Replace a Toilet Flange That’s Old or Broken

Turn Off the Water Supply

Photo: grigvovan / Adobe Stock

As with many other plumbing tasks, the first step is to turn off the water supply to the toilet so you don’t end up dealing with a messy leak. Look for the shut-off valve on the wall behind the toilet—typically located closer to the floor—and turn it all the way clockwise. 

Empty the Toilet Bowl and Tank

Now, it’s time to drain the water remaining in the bowl and tank and confirm that the supply line is fully closed. Flush the toilet a few times until the bowl no longer fills with water. You can use a plunger to drain any small volume of water lingering at the bottom of the basin. If the tank continues to replenish the bowl after a few tries, you need to go back to step one and keep turning the knob on the water supply until it’s all the way off. 

Disconnect the Water Supply

Photo: Elena Loginova / Adobe Stock

Set down towels or a tarp on the bathroom floor to keep it safe from the moderate water runoff that can happen while disassembling a toilet. Look for a hose, usually made of braided metal, that runs from the tank to the joint with the shutoff valve. 

Loosen it at the end attached to the fill valve on the underside of the toilet. If you have trouble doing so by hand, try using an adjustable wrench. Expect a bit of water leakage when the hose disconnects.

Remove the Toilet Tank

Look for the two or three mounting bolts on the bottom of the tank that connect it to the bowl on each side. Using your wrench, loosen the nuts from the bolts and set them somewhere safe and accessible. Carefully lift the tank up and off the bowl and set it aside. Take some time to review the parts of a toilet as you get ready for the next step. 

Remove the Toilet Bowl

Photo: New Africa / Adobe Stock

Now comes the hardest part. Be prepared to lift the toilet bowl—typically weighing between 70 and 120 pounds—off the ground. If you’re not confident you can safely lift and remove a toilet, you’ll need a helper on hand to help shoulder the weight.

The first step is to remove the caps from the bolts that secure the toilet's base to the floor. In most cases, there will be two of them on each side of the bowl. Use a screwdriver to pry off the caps, and then use the wrench to loosen and remove the nuts from the bolts. Set them aside for later.

Once you have removed the nuts, grab each side of the commode and gently rock it back and forth until it’s loose and the seal of the wax ring beneath the base breaks.

The bowl is now ready to lift. Straddle the toilet and crouch, reaching down until you have a grip on the underside of the bowl. Stand steadily and slowly, lifting with your legs, until the bowl is off the bolts. Set it down on its side on top of your tarp.

Scrape Away the Wax Ring

With the commode removed, you should see the outflow mouth of the drainpipe on the floor, surrounded by the flange and topped with the remaining pieces of the wax ring. Plug up the drain hole with some rags or an old towel to prevent as much of the unpleasant odor as you can from escaping—and to prevent anything else from falling in. Take your paint scraper or putty knife and scrape away the wax.

Unscrew the Mounting Bolts

Photo: New Africa / Adobe Stock

Most likely, you’ll find that the flange mounts to the floor with four screws. Insert your screwdriver and turn each screw counterclockwise until it’s loose enough to remove. If the hardware is in good shape, you can set the pieces aside to reuse with your new flange. 

Lift the Flange to Remove

The flange is a circular fitting (2 to 3 inches in diameter) that sits underneath the toilet; it connects the internal drainage system to the drainpipe while securing the base of the toilet to the floor. Most toilets feature a PVC flange sealed with a gasket. If yours does, with the wax ring scraped away and the bolts loose, you can simply lift it up from the drainpipe and set it aside.

Toilet flanges do, however, come in various materials and can feature different fitting types. If you reach this stage and it turns out you have a metal flange glued in place or attached with a deep-seal fitting, you’ll need to stop and hire a plumber to take care of the rest of the job. 

Otherwise, you can risk damaging the drainpipe—a significantly more expensive and complicated problem to address.

Before moving on to the next step, take the opportunity to examine the subfloor around your toilet. If any patches are soft or spongy, you should call a pro to quote the price to replace the damaged subflooring before proceeding further.

Measure the Outflow Pipe

Before installing a toilet flange, you’ll need to make sure you’ve got the right size. One option is to bring the old flange to the hardware store to find a match. Otherwise, you’ll want to take some measurements.

Before jumping into how to change a toilet flange, use the measuring tape to determine the diameter of the old flange, double-checking to confirm you’ve done it right. Make sure to buy a flange that matches the size, shape, and material of the old one—as well as a new wax ring if there isn’t one in your new flange kit.

Fit and Install the New Toilet Flange

Once you’ve got an appropriately-sized new flange, it’s time to start setting the new toilet flange. Remove and throw away the rags or towel from the outflow pipe.

Fit the new flange snugly into the outflow pipe, creating a seal with the gasket and resting the outer lip flush to the floor. Using the included hardware, secure the flange to the subfloor with screws and slide on the toilet flange bolts. Remember to tighten the washers or nuts fully.

Add the New Wax Ring

Photo: lightwavemedia / Adobe Stock

There are two different ways to install the new wax ring: Securing it either to the flange or to the toilet base. The latter is the preferred option among pros and the better choice if you have the space and muscle to do so. With the commode lying on its side on the floor or tilting it upward, attach the replacement wax ring directly to the hole at the bottom and ensure it’s fitted correctly.

If attaching it to the toilet seems too tricky, you can simply place the wax ring on the flange, centering it around the hole.

Replace the Toilet Completely

Photo: Pixel-Shot / Adobe Stock

With the replacement flange in place, all you need to do is reassemble the toilet. Lift the toilet from the floor—making sure to engage your leg muscles to avoid straining your back—and place it on top of the new flange. Be sure to line up the holes at the base with the flange bolts. Once it’s resting evenly, apply steady downward pressure from the top of the bowl to seal the wax. Be careful not to rock or wobble it so that you don’t break the seal.

With the hardware you set aside, secure each of the bolts on the bowl with the nuts and washers—turn them tightly enough to prevent the toilet bowl from wobbling but be careful not to over-tighten them and risk cracking the porcelain. Then replace the bolt caps.

Next, lift the tank and place it back on the bowl, aligning the bolts with the holes. With the nuts you set aside, tighten the bolts until the bowl and tank are evenly and securely aligned. Reattach the supply hose to the toilet tank. Slowly turn the valve to gradually open it, testing for leaks as water begins to flow back into the toilet. Once the tank has filled, flush the toilet and keep an eye on the base, making sure there’s no leakage at the base of the toilet.