Brand new toilet keeps running

[daytripper]

OK, I know nothing about plumbing, but we have a problem that's stumped several plumbers and contractors and I'm desperate for answers. We had a Sterling dual flush toilet, less than 5 years old, that started running. Had a contractor friend replace the ballcock, valve, etc. As soon as he left, the toilet started running again. A few days later, my brother-in-law, who went thru all the training to become a plumber but never pursued it as a career, did the same thing. You guessed it - as soon as he left the toilet started running!

We called several plumbers who said they wouldn't fix a dual flush toilet, so we decided to simply replace it with a Kohler single flush model. It was professionally installed three weeks ago. Today - you guessed it - the toilet started running. We're at our wits' end. Could there be some other issue with our plumbing that's causing this to happen? We have one bathroom so it's critical our toilet is working properly. Hope to hear your thoughts!

 

[Reach4]

When it is "running", is that temporary? Does dribbling a faucet make the "running" stop? What is the schedule of the "running"?

Take the lid off, and show us a photo of the tank inside. We will look at the water level, and the positioning of the refill tube, and maybe other things.

 

[Sponsor]

 

[Mliu]

My initial thought is that your water pressure is too high. Either you need a pressure regulator, or your pressure regulator is improperly set or defective, or you have a pressure regulator (or other backflow prevention device) but no expansion tank on the cold water line feeding your water heater.

 

[Mliu]

or you have a pressure regulator (or other backflow prevention device) but no expansion tank on the cold water line feeding your water heater.

Ok, let me "expand" on this (pun intended ), because a lot of people have never heard of a thermal expansion tank and don't know what they do or how they work.

Pressure regulators typically have internal backflow prevention. That means water from the street supply can enter your home's plumbing, but can not exit back out through your water main. This is good because it prevents the possibility of a problem in a home's plumbing from contaminating the water supply for the entire neighborhood. That's why, even in areas where the city water pressure is low enough that a pressure regulator is not required, some sort of backflow device should be installed.

So the water comes into your home and it can ONLY leave when you open a valve inside your home (faucet, shower, toilet flush, etc.). Guess what happens. You take a hot shower, run a load of laundry, wash some dishes, etc. You consume a lot of hot water from your water heater. That hot water is replaced with cold water. Cold water is less dense (takes up less room) than hot water. Then you leave the house for the day or go to sleep at night. Since no one is using the water while your away or asleep, no valves are open in the house. The cold water in the heater's tank starts heating up, becoming less-desnse and expanding, thus taking up more room. But where can it go? All the valves in the house are closed. Since water is essentially incompressible, as it expands with nowhere to go, the pressure must rise! And rise it does, throughout ALL the pipes in your house. This excess pressure can cause pipes to burst or valves to fail. That is what's likely happening with the valve in your toilet.

The solution is simple: install a thermal expansion tank in the cold water pipe feeding into your water heater (between the cold water shut-off valve and the heater). This is a metal tank with an internal air-pressurized rubber bladder (like a heavy duty balloon). That's because, while water is incompressible, air is very compressible! When the pressure rises from the cold water heating, the increase in water volume (because it's expanding) goes into the tank, compressing that big rubber bubble filled with air. Because the expanding water volume has somewhere to go, the pressure in your piping rises just a tiny bit (because of the slight increase in air pressure in the thermal expansion tank as the air bladder is compressed).

Having a thermal expansion tank will increase the life of your entire plumbing system: pipes, valves, and the tank of your water heater. Not only will it save you the cost of parts (like that toilet valve you keep replacing), and the cost of plumber service calls, but it can save you the HUGE cost of a flood if a pipe bursts within your home (which almost always happens when you're away, because that's what gremlins like to do ). Frankly, I don't understand why plumbing codes don't require thermal expansion tanks in every home or business, especially since they're fairly inexpensive. (The current codes may require them now, I'm not sure. But I've seen many recent homes that still don't have them.)

Besides installing a thermal expansion tank, you still should test and check your home's pressure regulator. If your home doesn't have one and your city water pressure is on the high side, then install a pressure regulator too. And also remember to periodically test your water heater's T&P safety valve. I know that very few people ever do this.

 

[daytripper]

When it is "running", is that temporary? Does dribbling a faucet make the "running" stop? What is the schedule of the "running"?

Take the lid off, and show us a photo of the tank inside. We will look at the water level, and the positioning of the refill tube, and maybe other things.

No, the running isn't temporary and dribbling the faucet made no difference. Basically, the tank fills normally after flushing but we continue to hear water and can see moving water at the bottom of the cylinder on the right side of the tank. Have attached a photo of tank as requested.

 

[daytripper]

Ok, let me "expand" on this (pun intended ), because a lot of people have never heard of a thermal expansion tank and don't know what they do or how they work.

Pressure regulators typically have internal backflow prevention. That means water from the street supply can enter your home's plumbing, but can not exit back out through your water main. This is good because it prevents the possibility of a problem in a home's plumbing from contaminating the water supply for the entire neighborhood. That's why, even in areas where the city water pressure is low enough that a pressure regulator is not required, some sort of backflow device should be installed.

So the water comes into your home and it can ONLY leave when you open a valve inside your home (faucet, shower, toilet flush, etc.). Guess what happens. You take a hot shower, run a load of laundry, wash some dishes, etc. You consume a lot of hot water from your water heater. That hot water is replaced with cold water. Cold water is less dense (takes up less room) than hot water. Then you leave the house for the day or go to sleep at night. Since no one is using the water while your away or asleep, no valves are open in the house. The cold water in the heater's tank starts heating up, becoming less-desnse and expanding, thus taking up more room. But where can it go? All the valves in the house are closed. Since water is essentially incompressible, as it expands with nowhere to go, the pressure must rise! And rise it does, throughout ALL the pipes in your house. This excess pressure can cause pipes to burst or valves to fail. That is what's likely happening with the valve in your toilet.

The solution is simple: install a thermal expansion tank in the cold water pipe feeding into your water heater (between the cold water shut-off valve and the heater). This is a metal tank with an internal air-pressurized rubber bladder (like a heavy duty balloon). That's because, while water is incompressible, air is very compressible! When the pressure rises from the cold water heating, the increase in water volume (because it's expanding) goes into the tank, compressing that big rubber bubble filled with air. Because the expanding water volume has somewhere to go, the pressure in your piping rises just a tiny bit (because of the slight increase in air pressure in the thermal expansion tank as the air bladder is compressed).

Having a thermal expansion tank will increase the life of your entire plumbing system: pipes, valves, and the tank of your water heater. Not only will it save you the cost of parts (like that toilet valve you keep replacing), and the cost of plumber service calls, but it can save you the HUGE cost of a flood if a pipe bursts within your home (which almost always happens when you're away, because that's what gremlins like to do ). Frankly, I don't understand why plumbing codes don't require thermal expansion tanks in every home or business, especially since they're fairly inexpensive. (The current codes may require them now, I'm not sure. But I've seen many recent homes that still don't have them.)

Besides installing a thermal expansion tank, you still should test and check your home's pressure regulator. If your home doesn't have one and your city water pressure is on the high side, then install a pressure regulator too. And also remember to periodically test your water heater's T&P safety valve. I know that very few people ever do this.

What would suddenly cause our water pressure to change? We've never had a problem in the 17 years we've lived in the home.

 

[Reach4]

Your fill level in the tank may be a little high, and water may be going through the overflow.
I would try turning the plastic screw with the + slot counterclockwise 2 or 4 turns or so.

To change the fill level more, see

 

[WJcandee]

I, too, would like to see the inside of the tank..

Sounds like there was a bunch of clueless parts-(and toilet)-replacing without any effort intelligently to diagnose the actual issue. Replacing the fill valve (ballcock) on a runny toilet should never be done without some diagnosing upfront, because the usual cause of a runny toilet is that the $4 flapper needs to be replaced. (On a dual-flush, it's usually a leaky rubber seal -- about $2.) So, I deduce cluelessness from the fact that the ballcock was just willy-nilly replaced.

So, here we go. Diagnosing. By "running", do you mean that you hear the fill valve putting water into the toilet tank?

If so, what happens to the water going into the tank?

Option A: Does it raise the water level? Does it raise the water level to the point that some water starts to run into the overflow riser, even though the toilet normally shuts off 1/2" below the top of that valve? (If so, one possible diagnosis is water pressure that is sometimes too high.)

Option B: Even though you hear the toilet "running", does the water level remain below the level of the overflow riser? (If so, the typical diagnosis is that the flapper has degraded and water is flowing past it and out of the tank slowly. The fill valve comes on to refill the lost water. Another possible diagnosis is that the refill hose is stuck down into the overflow riser (tube), and siphoning water through the fill valve and out of the tank down the overflow riser. To check between the two, first make sure that the refill hose is daylighted above the top of the overflow riser on a clip. Does that solve it? If not, then try marking the water level in the tank with a pencil. Turn off the water. Leave the tank overnight. If the water level falls, you have a leak from the tank to the bowl, usually past the degraded flapper, so the problem can be solved by replacing the flapper (or seal in a flapperless toilet). [On rare occasion, and I have spotted it in photos for people, there is a crack in the plastic overflow riser that is allowing water to pass through it.] Possibly, the wrong flapper is being used or the flapper seat on the flush valve has accumulated gunk and needs to be brilloed.)

Option C: On the Korky 528 fill valve (which you may not have), gunk can accumulate on the little teensy one-way valve at the base of the float chamber, holding it open. When the water rises on refill to the bottom of the float chamber, water enters the chamber through the held-open valve and shuts it off too soon, whereas it normally would rise to the shutoff level and flow in the side of the float chamber, not the bottom, causing a firm shutoff. It then starts to stutter because there isn't enough water in the float chamber to keep holding the float high enough for a good shutoff. Easily fixed.

Those are pretty-much the options, although there are some esoteric ones. I would go through this diagnosis procedure, and let us know what you find. Usually these issues, although seeming mysterious, are easily solved.

 

[Mliu]

No, the running isn't temporary and dribbling the faucet made no difference.

If in fact, you did have a high-pressure problem, it could have blown-out a seal in toilet valve. After that, the valve will continue to leak even if the pressure returns to normal. So dribbling the faucet at this point won't help.

 

[WJcandee]

What would suddenly cause our water pressure to change? We've never had a problem in the 17 years we've lived in the home.

If you have an expansion tank, they can, over time, become waterlogged and therefore useless. A pressure reducing valve (which lowers the often-much-higher pressure in your municipal water system after it comes into your home) can also begin to fail.

Sometime in the last 17 years, it's also possible that the municipality replaced your water meter and/or the municipality required a backflow valve (new meters often have a backflow valve installed at the same time). [In the old days, your house was open to the municipal water system, so excess pressure in your house would be absorbed by that much bigger system. Once a backflow valve (or meter/backflow valve) was installed to protect the public water system from any possible contamination of your home water supply, excess pressure (usually from your DHW system [domestic hot water]) has noplace to go, because your pipes don't expand with the pressure.

It will usually find its way out the weakest link, which is often an outside hose bib or toilet fill valve.

Easiest way to check whether the pressure is too high is to buy a $5 water pressure meter with a little moveable telltale that will mark the highest pressure, then screw it on a hose bib or whatever, open the valve, and check the pressure. If it's already too high, diagnosis over. If not, leave it on for 24 hours and see what the highest pressure was.

Looking at the picture of your toilet, it seems that the water level is at the top of the overflow riser in your canister flush. That is possibly a reflection of: (1) pressure pushing past the fill valve after it shuts off [i.e. from excess pressure]; or (2) the fill valve shutoff level needs to be set lower (i.e. improper adjustment of fill valve at installation).

If it isn't overflowing a little, then I would also check the the refill hose isn't shoved down into the overflow riser; it's hard to see from the photo if it just ends at the top or whether it's down in there.

Good luck! Let us know.

(It is likely, but not conclusive, that the same problem (i.e. pressure) caused the issue in both toilets, but it also could be a coincidence and the issues with both toilets have different causes (i.e. leaky flapper in the old one but simple misadjusted fill valve in the new one).

And I agree with much of what Mliu says, but I should also point out that the effects of excess pressure are often not as dramatic as he is describing. For example, pressure rises above what the weakest link can handle, but not much more, so nothing "blows out" or is destroyed. Instead, what can happen is that you can have a little dribble from a hose bib for years, on and off, that nobody notices because it's not one you normally use. Or whatever.

 

[Mliu]

What would suddenly cause our water pressure to change? We've never had a problem in the 17 years we've lived in the home.

Several possibilities:

1. The city water pressure might have recently increased. For example, this could be the result of old equipment being upgraded. As cities grow, demands on the water supply increase. If no improvements are made, water pressure will drop as more homes (water users) are added. At some point, the city will have to add more capacity and that can cause the municipal water pressure to rise.
2. If you have a pressure regulator in the supply to your house, it could have failed.
3. A backflow could have been added to your supply line. Older homes often had neither pressure regulators nor backflow prevention devices. Although the water company won't come and install a pressure regulator for you, many cities are replacing old water meters with new "smart" meters that don't require a "meter reader" (i.e., a human) to go to every house to read the meter. The new smart readers typically use some type of radio signal to transmit your meter reading back to the company. I believe that all new meters have backflow prevention built into them.
4. Age. As your plumbing system ages, it changes. Pipes build up scale. Metal "work hardens" from repeated flexing and fatigue. All these things can contribute to your plumbing becoming less flexible. Softer pipes (and water heater tanks) are able to flex and absorb some pressure. Harder pipes are the opposite. It's just like the way your body works: as it ages, your blood vessels harden, causing your blood pressure to rise.

These are just a few things I can quickly think of off the top of my head.

 

[Mliu]

Well, it looks like Wjcandee beat me to the punch. And yes, you absolutely should test your home's water pressure.

While he's correct that the effects of excess pressure are not always dramatic, they can be. Do you want to roll the dice and hope that you only get a leaky hose bib, rather than a burst a pipe inside your home? I raise the worst case scenario because they can and do happen, and the results can be disastrous (and VERY EXPENSIVE). My goal is to motivate people to bite the bullet and shell out the couple of hundred dollars to install a thermal expansion tank. Because, in the long run, it's very cheap insurance compared to what might happen if you don't. For the record, I'm not a plumber nor do I own any stock in plumbing supply companies, so I have no interest in advising you to install a thermal expansion tank other than it could save you many thousands of dollars in damage.

And if you still think you might just end up with a leaky toilet valve or hose bib, consider this: in my (relatively short) time on this earth, I've personally witnessed two catastrophic plumbing failures caused by high water pressure due to lack of a thermal expansion tank.

The first was at my mom's house decades ago. Her water heater tank literally split down the side. Of course, this happened when she was out-of-town on vacation. Fortunately, her water heater was in an unfinished basement so the water just ran outside and down the hill and didn't damage her home. (Neighbors noticed the waterfall and alerted me so I was able to come shut off the water before too much was wasted.) But she still had to buy a new heater (yes, I installed it along with a thermal expansion tank). And she had to deal with a very high water bill that month.

The second time was when I first moved from California to Colorado. I rented a house to move into because I wanted to learn the area before buying. Less than 3 weeks after moving in, we were out one late-afternoon/evening to attend a school function for my daughter. After the event, we stopped to do a little shopping on the way home. We were out of the house about 3 hours. When we got home and I opened the front door, I was greeted by a hissing sound and the smell of chlorinated water inside the house. I immediately knew what was wrong and scrambled to the basement to shut off the water main. During the short time we were out, a faucet supply hose under the kitchen sink had burst. Sure enough, there was no thermal expansion tank, even though the home was built in the mid-1990's. Realize that this was in mid-January and the outside temperature was well below freezing. What happened is that we had all showered prior to going to the school function. That drained most of the hot water out of the heater. It was replaced with water that was ice cold (thus very dense). The temperature difference was huge, so a lot of expansion occurred as that cold water was heated. Because we went out after showering, no one was home to occasionally use some water and relieve the pressure in the home's plumbing. So it rapidly spiked and blew out the weakest link, which happened to be the plastic kitchen faucet supply hose. The split was tiny, less than a 1/4 inch. But because that small high-pressure spray was unattended for a couple of hours, a tremendous amount of water was released into the house. The wood kitchen floor was flooded. The wood family room floor was flooded. And the partially-finished and carpeted basement was REALLY flooded. (As I said, gremlins like to do their worst mischief when you're not at home.) Fortunately, I had both a shop vac and a rug shampooer to suck up the water, but it took us working through the night until the next morning to clean up the mess. (After we cleaned the initial mess on the kitchen and family room floors, I dashed out to Home Depot before they closed for the night and bought a high-powered fan. A fan is the ONLY way to thoroughly dry out a flooded interior after you've sucked up all the loose water. I ran the fan in the basement with the windows open for a week to ensure all the moisture was dried out so that no mold could grow.) Because we caught it quickly and got all the water sopped-up so fast, no damage was done to the home. However, because we had just received delivery of our household goods from California the week before, we had a lot of unopened boxes in the basement that got wet. A bunch of our personal property was destroyed or damaged. Imagine if that had happened just after we left for a couple of week's vacation.

Did I mention that a thermal expansion tank is very cheap insurance?