Toilet repair and adjustment questions and answers

Toilet repair and adjustment questions and answers

Toilet Repair, Adjustment and Troubleshooting Q&A


Dear NH:

I need some help and couldn’t find the answer in your site. Our toilet bowl does not have enough water in it! Yup, a daily mess because it doesn’t flush completely most of the time. Please help us!!


If you have a typical residential toilet, there is a flexible rubber or plastic tube that is attached to the inlet valve. It runs to a long, vertical tube in the center of the toilet called the overflow tube. That’s it right over the flapper.

When you flush the toilet, this tube redirects some water into a vertical pipe to which the rubber flapper is attached. This additional water is what controls the level of the water in the bowl. If this tube is not supplying water. either because of a defect in the tube such as a kink, defect in the inlet valve itself, or if it has been disconnected or moved. the bowl will have too low a water level for an efficient and thorough flush.

If the tube is kinked, try to unkink it or replace it. These tubes occasionally become very stiff and even brittle when the homeowner has used bleach-containing toilet cleaning products in the tank. If you find that there is no water flowing through the tube, even though it is not kinked or blocked, your intake valve probably needs to be replaced.

If you have an unusual low flow toilet or some of the older odd brands, this won’t be of much help BUT the concept is the same water must somehow get into the bowl as the tank fills so that there is enough water for a proper flush. Many plumbing supply stores are happy to help you troubleshoot unusual toilets as long as you can supply some basic information. Aside from the brand name, useful information is often times stamped onto the inside of the toilet tank lid.

You might also want to check the water level in the tank. Is the level of water up to the water line mark? If you can’t see a mark, use the overflow tube as a guide. The water level should be about an inch below the top of the overflow tube. If not, adjust the inlet valve to raise the level.

To conserve water, people often install displacement devices in the tank. water dams, water bags, etc. for water conservation. The strength of the flush is affected by these, so if your flush is still balks, remove them.

Dear NH,

Do you know of a way to repair a broken toilet base? When reseating the toilet I broke the flat portion of the base around the bolthole. Will a heavy duty epoxy work?

GJ from Hurst,TX


I can usually come up with a repair or at least offer some hope, but in your case I’m hesitant. Toilets are made from clay, baked and glazed to a smooth finish. Though they appear to be very tough, an abused toilet will break just like a ceramic plate! Sometimes a temporary emergency repair can be made to a cracked bowl or tank (neither of which I recommend). The break you describe is at a high-stress area of the toilet. There is no adhesive that exists today that I would trust to make this repair. Should it re-break when the toilet is being used, severe leakage around the wax seal under the toilet could occur with dire consequences!

The break probably occurred because you overtightened the mounting nut, causing the ceramic to crack. Another possibility is that the base already had a slight stress crack that finally gave way during reinstallation. Old toilets are particularly prone to this sort of breakage. Also, if the floor is uneven, the toilet might rock and appear to be loose even though you’ve completely tightened the bolt.

Breakage during installation is the most common toilet installation problem and even happens occasionally to pros. Why? Because the mounting nut never really feels tight, making it too easy to accidentally overtighten it! For future reference, the tightness of toilet mounting nuts is judged by the stability of the toilet, not the apparent tightness of the nut! If the toilet easily turns or wiggles under pressure (either by hand or by actually sitting on it), then it requires a little more tightening.

There is one exception. If the floor is slightly uneven (which should be obvious by looking under the base of the toilet) breakage is even more likely since the entire base may not be tightly against the floor! Careful tightening followed by caulking around the toilet base will give sufficient support and stability. Remember, tighten the nuts firmly just not too aggressively!

IF YOU ARE DETERMINED TO TRY AN ADHESIVE. my choice would be polyurethane glue. This form of glue is very strong and sticks to almost anything! If anything will work in this circumstance, polyurethane glue is it!

Polyurethane glue expands as it dries, so you don’t need to slather it on. a thin coat on one side is plenty. The surfaces should be slightly damp. Because of the expansion, it is important to clamp the broken part in place. This might be tricky but without clamping the expanding glue will move the part and create a bad joint! Once dry, the excess glue can be scraped or sanded off.

Dear NH,

After replacing all parts in my toilet tank, I continue to have a minor leak into the bowl. I’ve installed five new and different style flappers and two new flush valves without success. The water fill valve is new and seems to work fine. Moving the flappers around to possibly find a better seal has not worked. The leak is only a small drop of water. I would appreciate any suggestions you could give me on this problem.

DM from Lantana, Florida


So what you are telling me is you have replaced every part in the toilet multiple times and you still have a leak? Seems impossible, right? Well, it is. What you may have is an apparent leak that isn’t a leak at all!

Instead of the toilet draining completely after a flush, an accumulation of slime, grit, remnants of in-the-tank cleaning tablets, etc. has partially blocked one or more of the holes underneath the rim of the bowl. These holes cause the swirling action typical of vintage toilets (modern low-flow toilets have a different flush style).

A slight blockage in these holes will cause an accumulation of water within the rim of the toilet. Not a lot. it could be as little as 1/4 cup. But, drop by drop, 1/4 cup of water can drip for quite a while.

Rather than try replacing more parts, check the toilet first thing in the morning after it has sat undisturbed for many hours. Hopefully, you will find that there is not really a leak. just a slowdown!

Dear NH,

I am a maintenance man for a property management company. One thing you missed in your section on repair of slow flushing toilets is the little holes under the toilet bowl rim. If these get plugged with calcite or crud, you can clear the blockage by using a compass point, paper clip, or other solid, pointed object. Simply insert it into the holes, one by one, to open them up. Be aware that they are at a slight slant, but if you get them open, this simple fix may cure slow flushing problems.


Dear NH,

Our 3 year old hillside home has the lower floor built on a slab. The toilet in the lower part of the home does not flush very nicely. Even if there is no waste in the bowl, it seems to flush up (complete with a large air bubble) and then out. This toilet backs up constantly and has overflowed at least 10 times since we have lived here. Seems like only a very minimum amount of waste can be flushed. Do we need a new toilet or extensive pipe repair??

JT from Madison, Alabama

Dear JT,

The first step would be the most conservative. Turn off the water to the toilet, drain the bowl and tank, and unbolt it from the floor. Turn it over and look for obstructions either within the bends of the toilet itself or immediately under it in the drain. Sometimes objects can lodge within these areas, and removing them can solve what appeared to have been a major plumbing blockage. These types of blockages can be deceptive, allowing water to pass by without a whimper, but causing a clog as soon as any paper or other stuff is flushed by them!

I had one client who had a toilet backup and asked me to take a look. When I realized that the blockage was between the toilet and the city sewer, I referred her to a great local plumber. When the plumber began to investigate the blockage though one of the main cleanouts, he noticed that the pipe connecting the house to the sewer was partially disconnected just outside the foundation. A do-it-yourselfer would have most likely missed this (though, admittedly, many plumbers may have, too). Eventually, the leaking sewage waste would have made its way into the basement and caused a major calamity. Not that the total repair was inexpensive my client had to have the front of the house excavated to expose and correct the problem. And then re-landscaped to boot! But at least the ramifications of this sewage leak were limited to the outside.

Dear NH,

I notice that my second floor guest bathroom toilet bowl will become empty after sitting unused. I also have a water spot on the ceiling directly below the bathroom. There is no evidence of water on the floor in the bathroom, though. Can the water in the bowl water leak around the seal under the toilet without showing on the bathroom floor?

EN from Loveland, OH


Toilet repair and adjustment questions and answers

Leakage around the toilet flange seal, or wax ring, and the water draining from your bowl have no obvious connection to each other. The water in the bowl cannot escape any more easily than water in a coffee mug (unless you’re a klutz and knock it over). This leads me to believe your toilet bowl may have a small crack in it.

Since you have evidence of a leak via the water spot on the ceiling below, I would take action immediately. This would consist of draining the toilet of all water, disconnecting it from the supply line, unbolting it from the floor flange and turning it over for a look-see. It should be fairly obvious if the toilet has a crack because water leaks generally leave telltale signs such as discoloration or mineral deposits.

The wax ring can also develop a leak but that would not account for the water disappearing from the bowl. The only water that passes by the wax ring is the water leaving during a flush. The water that remains in the bowl is there precisely because it is below the level of the toilet’s built-in trap. Of course, you could have both problems. Removing the toilet will allow you to diagnose both.

You could also have a leak in the drain pipe, but I would err on the conservative side and leave that issue out of the repair equation. for now. Once you are sure that toilet is not broken (or you get a replacement) AND a new wax ring is properly installed, you should then be concerned if the water stain on the ceiling becomes larger. Before repainting the ceiling, give it at least a few weeks to thoroughly dry out.

If the leak still exists, the next step would require cutting open the ceiling beneath the toilet. not a conservative effort to say the least but in some cases necessary!

Can a toilet leak with no obvious evidence? The answer is an unqualified yes! Fact is, most slow toilet leaks are NOT detectable because they develop slowly. This has to do with the design of a toilet drain. The drain flange, the top part of the toilet drain to which the toilet is attached, comes through a hole in the floor. Most small leaks will not appear around the base of the toilet but instead either travel down the drain pipe OR creep under the flooring material since the flange is at the same level or slightly beneath the level of the finished floor. This is true regardless of the flooring material. tile, vinyl sheet, vinyl tile or one of the newer plastic laminate floorings.

This stealth-type of leak is the most damaging because it can go undetected for many months or even years until the ceiling below becomes stained and moldy or, worst case, the plywood subfloor under the toilet begins to weaken, rot or warp. Vinyl flooring can cause the worst subfloor rot because it is nonporous; the trapped water cannot easily evaporate. Tile is a close second since it is also nonporous. Unfortunately, a wobbly toilet is often the first symptom of serious deterioration in the floor.

About 5 years ago, a client needed a toilet removed for a vinyl flooring installation. When I lifted the toilet, the floor underneath was soaking wet, the dampness extended for a few feet on every side of the toilet under the old vinyl flooring. The wood was thoroughly soaked and quite rotten in spots.

As if that wasn’t bad enough, within minutes the room was flooded with carpenter ants! They had detected the soft, rotten subfloor and made a substantial nest. right between the layers of plywood! All in all, a four-foot square section of floor had to be replaced before the new flooring could be installed. The customer afterwards commented that they had an ant problem for years, but spraying never seemed to help. now we know why! Who would have thought that the ants were nesting under a second floor toilet!

Dear NH,

I have a flapper that seems to have formed a vacuum seal. I have to put all my weight on the handle to get it to flush or lift the tank lid and pull the chain manually. Do you know the cause and a fast, inexpensive way to correct? I now have a metal flush arm in the tank because I kept breaking the plastic ones and got tired of replacing them.

VF from Katy, TX

Dear NH,

I found your website through Yahoo while trying to find out how to stop my toilet from wobbling. It rocks front to back. I took it out to change the flooring and it is still unsteady. I have taken it apart and replaced it twice now! The top of the flange is in. above the floor. I measured the clearance inside the bottom of the bowl and it seems that it should reach the floor but it doesn’t. The front is about 1/4 in. too high (a wood shim at it’s thickest part goes under easily).

Dear S,

A high flange is unusual. usually the rim of the flange rests on the floor. There are a number of possible reasons why the flange would have moved, but my speculating wouldn’t be helpful to you right now.

One suggestion would be to hire a plumber to lower the flange. This would require either opening up the floor OR the ceiling below. not a cheap job! Another option for a do-it-yourselfer would be to build up the floor under the toilet.

In the case of minor wobbles, I have suggested using a mildew-proof latex bathroom caulk to basically glue the toilet in place. However, if the toilet is actually off the floor a little, you should probably add a custom-sized spacer under the bowl.

This is easier than it sounds. First mark the profile of the toilet on the floor. Then remove the toilet and place it on a piece of plywood of the proper thickness. in your case 1/2 thick would probably do the job. Trace the shape of the toilet onto the plywood. Cut the plywood to match the profile.

Then, cut a hole in the center of the plywood for the flange, using the line you drew on the floor as a guide OR use measurements from the bottom of the toilet. your choice! The hole doesn’t have to be absolutely precise. it just has to allow the plywood to sit flat on the floor around the flange, matching the line you drew around the toilet bowl.

Once you have completed the cuts, place the plywood on the floor over the flange and reinstall the toilet. If you prefer (I would), waterproof the plywood with a sealer such as Thompson’s Waterseal. Wait a few days before installing the sealed wood. Then after a week or so, you could put some caulk around the exposed plywood edge to further protect it from moisture when you wash the floor. Now it’s your turn!

Leave a Reply