Home & Garden Columns

Flushing toilets account for nearly 30 percent of our water usage and with water bills at an all-time high, I thought it might be time to talk about how to replace a toilet. (It’s also a VERY green thing to do, since the system that supplies water to our homes contributes greatly to CO emissions.) 

This is actually a fairly simple job but I’ll try to show you where the tricky parts are. Nonetheless, this is a much more manageable job than many plumbing chores, and not beyond the skill of a beginner if you pay attention and work thoughtfully. 

First, a single-piece toilet will be simpler to install than a two -piece, though they tend to be somewhat more expensive. With a single-piece, there will be almost no set-up. With a two-piece, you’ll have to put the two parts together using a rubber seal that sits between the two parts and two (sometime three) bolts that you’ll be installing to hold the two parts together. 

First, determine the distance from the center of the flange (that’s the ring that the toilet attaches to and represents the first part in the piping that leads to the sewer). This is simple because the two bolts that you can see on either side of the base of the toilet (or the white caps covering them) site just to the left and right of the center of the flange. So measure the distance from the center of the bolts (you can pop the caps off using either a narrow flat screwdriver or a firm putty knife. They snap on and pop off. Measure the distance from the center of the bolt to the wall (think about trims and other items that may come forward of the wall and account for them too). Measure the bolts on either side and average the two as these may be slightly off center (one more forward and one more backward).  

When you buy your new toilet, be sure that it will fit with that distance from the flange center. This is a great question for the purveyor of said toilet and a great reason not to shop at a big box store, as they are not likely to understand the questions (assuming you can even find someone to ask).  

A typical recommended distance is one foot but some toilets are closer to 11 inches, and it’s best to be sure that your new toilet will fit without a struggle. As a rule, newer toilets fit easily where older toilets has formerly resided. 

If you’ve bought a new two-piece, you’re going to want to follow the instructions carefully in putting it together. The bolts that hold the toilet parts together may already be installed on one side, but if they’re not, it’s very important to get the order of parts right. There must be a seal or rubber washer on the inside of the tank that goes onto the bolt before any other part. This keeps the toilet from leaking at the bolt. There will then be a washer and nut (usually) on the outside of the bottom of the tank. Once these are tightened to a fairly firm setting, the bolts can then be fed through the holes in the bowl and then tightened with the appropriate washers and a nut as per the instructions. Get these washers and nuts in the right order. It’s one of the tricky parts of this job. 

When your toilet is all together and ready to go, you can take the old toilet off. You’ll need to pop those caps off (if you have caps) and the use a small adjustable wrench to remove the nuts. Turn off the water at the shut-off valve next the toilet and use a cup to remove as much water as you can after you’ve flushed. The more water you are able to bail into sink, the less you get to mop up after you’ve started to remove the toilet. This is, nonetheless, a wet job. 

Remove the flexible connector from the bottom of the toilet. Some of these are actually fairly rigid and may not fully disconnect until you lift the toilet. 

It’s not a bad idea to get help with this part if you can, but a strong individual can lift a toilet off a flange and move it across the floor to a safe spot. 

I would always recommend installing a new flexible connector from the valve to the toilet. Be sure to take the old one to the store to get the size of the connection at the shutoff, though they are usually 3/8”. The other size will be a typical toilet connection and is standardized. Just buy a “toilet” connector (but they’re 7/8” just in case). 

The next part is the trickiest. You will need to remove and replace the old wax seal. This requires some study of the new toilet. Using a putty knife, remove as much of the old wax as you can. Now, I’m very old fashioned and I like the plain wax rings, but there are times when the new ones with plastic inserts can be helpful. But be cautious; the plastic insert doesn’t smoosh (yes, smoosh is a word!) into place the way wax does, so if the toilet fits to the flange very tightly, it may end up holding the base of the toilet up off the floor and may even cause a leak. I usually show up with at least one of each kind and look at it to decide what I want. If the flange sits well below the level of the finished floor (the tile or linoleum or whathaveyou), you may need two stacked one on top of another. This isn’t ideal but it usually works. There are special flange shimming devices but I’m not a fan. For me, more is less. So place your wax seal (or seals) so that they will stand higher than the point under the toilet where they will make contact. Excess wax will find its way out into the space under the toilet. Better a too much than too little but the ideal fit has you pushing the toilet down a bit. I tend to get on the seat facing the wall and sort of ride it down until it touches the floor. 

Now, backing up, before you put the toilet onto the flange you’ll be checking or replacing the toilet bolts. These are the ones that actually hold the toilet to the flange. These might be fine and can be left in place. If you’re not sure, they are not expensive. I tend to replace them as a matter of course but there’s always room for an exception. The toilet bolts fit into slots on either side of the center point of the flange. When you see the old ones in place, you’ll see just how to slide them out and slide the new ones into place. It’s a very cool system, but they seem to work best when there are an extra set of nuts and washers that hold the bolt to the flange so that they want to aim straight up to meet the holes in the toilet. Otherwise, it’s a bit floppier a situation and when you’re holding a toilet in the air over the flange, everything can be a little hard to align.  

So now you’re ready. Pick up the toilet by the sides of the bowl and gently find the bolts through the holes and slowly push it down until we meet the ground. It should feel snug and not slide easily from side to side. The wax should be gripping the toilet somewhat and the toilet should not rock. 

Finish by putting a new set of cap bases on (be sure to have them right side up. They have an up side stamped on most), then a washer and then a nut. Tighten the nut until it feels tight enough to keep the toilet from moving at all. That’s it. No tighter. It is china after all and can break off and that’s no fun at all. When you feel like the toilet is nice and tight. Install a cap over each cap base. Connect your new flexible water line nice and tight on both ends. Also be sure that the fill valve that sticks out of the bottom of the toilet is nice and tight too. Some come from the factory a bit loose and we don’t want a leak (or a flood). Building codes call for toilets to be sealed to the floor (usually done with a bead of caulk) but I have to confess that I am divided on this due to concern that a leak at the flange will not present itself for ready view on the floor but will instead act insidiously until the floor has rotted away. 

When you buy your new toilet, take the time to look at the ultra-low flow and dual flush models. These can greatly decrease your water usage and most now work quite well. This job may be able to pay for itself in under a year, given the high cost of water so what are you waiting for. And your husband says you never do anything nice for him!