pipe leak in wall behind toilet?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by 702jerry, Sep 19, 2013.

  1. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    I live alone in a somewhat small 3 bedroom, 2 ½ bath house. A couple of nights ago (Tuesday 9/17), I flushed the toilet in the guest or 2nd upstairs bath. Later that night I walked by the bathroom and heard a constant dripping noise. On inspection I didn't see any water near the toilet, bathtub or under the bath sink. I thought it might have been coming from inside the toilet tank. I also noticed that once in awhile it would make a noise like it was refilling the tank or bowl. Exhausted from a very long work day, I just went to bed and decided to check in the morning.

    The next morning around 10:30 a.m. the constant dripping sound was still there, sounding almost like the patter of light rain on the roof. I put my ear to the wall and heard what sounded like dripping from inside the wall. Running late for work, I turned off the master water switch for the house and left.

    Later that night about 11:00 p.m. when I came home, before turning the water on I went upstairs to listen for the dripping noise. It was not there. After the main water switch was turned back on I checked again. This time the dripping noise was back.

    At this point I took off the lid on the toilet, there was water or condensation under the lid. I then flushed the toilet twice to see if there was any change. The dripping continued. I did notice that the water in the tank would slowly go down for no apparent reason. Then I put some vinegar in tank and waited about 10-15 minutes. Some of the vinegar was making its way into the bowl.

    Then I turned off the water switch just for the upstairs 2nd bath toilet and flushed the toilet so all the water would clear out of the tank. After about 5 mins the dripping noise slowed to a stop.

    The last test that I did was to turn on the water to the toilet, then quickly run the 15 feet to the toilet and hold the fill valve to prevent water from going into the tank. At this point I put my ear to the wall, still holding the fill valve and clearly heard dripping from behind the wall.

    So this is where I am at now. The water to the affected bathroom is off, no more dripping noises. Would you agree that there is a water leak? (could it be something else?). If so given that it only leaked about Tuesday afternoon to Wednesday morning, realistically how much damage could have been done?

    The house is 7 years old. I've only been in the house 13 months. Unfortunately, the home owner's warranty expired last month and I did not renew it. After a large auto repair expense, I don't have the money right now to have a plumber tear out the dry wall and fix a pipe. I might have the money in three to six months. Do you think I could wait that long before any mold growth got to bad? I live in Las Vegas where the air is very dry.

    This bathroom is rarely used and in fact had not been used since the bath tub faucet was replaced by a plumber about a month ago (and also in the master bath too. Both were replaced due to a loud whistling noise). I know the plumber had to push very hard to get the tub faucet on. Not sure why it took so much force. Could that have possibly caused this problem?

    Any similar experience or advice would be greatly appreciated.
  2. wjcandee

    wjcandee Wise One

    Messages:
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    Location:
    New York, NY
    It sounds like a leaking flapper. Your toilet tank has a device that lets water in (the "fill valve") and a device that lets water out (the "flush valve"). Depending upon what type of toilet it is, it will have one of several types of flush valve. The most common is a "flapper" that is lifted when you pull the flush handle ("trip lever"), thus letting water flow from the tank to the bowl. The flapper floats in the water for a moment, and then closes to stop the water from leaving the tank and allowing the tank to refill with water from the fill valve. The flapper (or whatever device is blocking the flush hole) is rubber or similar, and will wear out after a while.

    When the flapper wears out, a little bit of water will drip from the tank into the bowl. After it drips from a full tank for a while, the toilet will start to run just a smidge so that it can replace the water which leaves the tank, and then turn off. When it isn't running, a little water is still leaving the tank past the flapper, going into the bowl very slowly, and then dripping out of the bowl and into the drain pipe for the toilet. That is likely what you are hearing: the water dripping from the toilet bowl into the drain pipe for the toilet. (To put more color on it, the toilet bowl, when properly refilled, settles to a specific level. Any more water that dribbles in will also dribble out over the "weir", down the trapway, out the outlet, and into the drain pipe under the toilet, then into the vertical drain pipe in the wall, down to the underground main drain, and out to the sewer. While the toilet water level is settling and if there is a little leak from tank to bowl, then that little leak will dribble over the weir and down the pipe in your wall...drip, drip, drip.)

    [​IMG]

    Do this test. Turn off the water to the toilet and see if the tank doesn't go down some while the water is off. (What we do is mark where the water level is in the tank with a pencil, then come back in a couple of hours and see whether the water level has fallen. Or leave it overnight and look in the morning.) If the water has drained down, most likely you need to replace the flapper or other device. Look in the tank and tell us what model numbers you see in there (or better yet post a picture of the inside of the tank), and we can help you determine what kind of replacement flapper (or other device) you need. Flappers cost less than $10, usually, you can get them locally, and they will take you less than ten minutes to change out with no need for tools. But there are all types of flappers for all types of toilets, so we need to know what you have so we can point you in the right direction.

    Good luck and let us know.
    Last edited: Sep 19, 2013
  3. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    Wjcandee,

    Thank you very much for the detailed information! That is very helpful.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    After the toilet has refilled from a flush and the valve has shut off, turn the shutoff for the toilet off and leave it. If the tank empties, as I'm pretty sure it will from your vinegar experiment, you'll know for sure that that flapper valve needs to be replace OR there's some crud caught where it seals, and it's leaking there. Much more common to just have a worn out flapper valve. If it is leaking in the wall, over a couple of months you could have some significant rot start up. That area is contained, and your low humidity won't help much (some, but not much) like it would if it were open to the air. Worse comes to worse, cut a hole in the wall and look. If it is wet, you may be able to identify exactly where. Plus, having it open to the room means it can dry out easier (may not happen if the leak is bigger than what can evaporate, though). If you are careful when making the cut, you can replace that section as a patch plug, and taping the seam isn't that big a deal. You will need to repair the paint, though.
  5. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    wjcandee and jadnashua,

    Great info thanks! I should mention that I work about 50-55 hours in the space of four days so I haven't had time to do additional tests yet. I have three days off starting Sunday so I should be able to do these tests at that time and will get back to you.
  6. wjcandee

    wjcandee Wise One

    Messages:
    1,934
    Location:
    New York, NY
    Great! Take your time. No rush. We'll be here!
  7. craigpump

    craigpump Active Member

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    Location:
    ct
    A few drops of liquid food coloring in the tank will show a leaky flapper too. If the bowl turns the color of the food coloring, you know your flapper has a problem.
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    That works well, but if you leave it overnight, both the tank and the bowl may end up clear! Means the same thing, though...it's leaking and needs to be fixed.
  9. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    UPDATE:

    Definitely a flapper problem. On turning on the water to the toilet the tank was filling slowly because water was leaking into the bowl. I put my finger on the front edge of the flapper and the tank was able to fill in a more normal fashion. The dripping sound started immediately on turning on the water to the toilet.

    After the tank filled the water level in the tank almost immediately started to drop. As it was going down I flushed the toilet again. Again I held down the flapper as the tank started to fill. Oddly the overflow tube started to fill up as the tank was filling and at one point started to overflow.

    After the tank was full the water level in the tank started to fall again. I flushed and this time as the water was filling the tank, with the water level still low, I put in several drops of red food coloring (special wal-mart trip just for that... I don't cook). The red food coloring showed up in the bowl right away. So clearly its leaking into the bowl.

    So the dripping sound is probably the water dripping out of the bowl and into the drain pipe for the toilet. What I don't user stand is why does it do that? Why would water drip out of the bowl and into the drain pipe, even when there is little or no water in the tank?

    Of course next step is to replace the flapper. I bought a fluid master universal #501 flapper. I should have time to replace it Tuesday and report back.
    Last edited: Sep 23, 2013
  10. wjcandee

    wjcandee Wise One

    Messages:
    1,934
    Location:
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    I will take your word for it that the Fluidmaster will fit -- "universal" isn't completely universal -- but on a generic toilet it should. Me personally, I like the Korky flapper. Their basic one (black) works well on most toilets, but if the Fluidmaster doesn't fit, come back here or call Korky at 1-800-LAVELLE (the manufacturer of Korky) and they will happily tell you which one of their made-in-Wisconsin flappers will fit your toilet. (Fluidmaster is hecho en Mexico.)

    As to why the water would drip from the bowl, even when there isn't much water in the tank -- simple. If you look at the diagram above, you can see that the toilet bowl really is a "bowl". Part of the bowl is hidden from your view, and constitutes the beginning of the trapway. The bowl will fill to a certain level and then can fill no more. Drip a little in and that will drip over the "weir" and down the trapway into the drain -- as if overflowing the side of a bowl. Urinate into a toilet and, although you probably don't notice it unless you are listening very carefully, you can hear the displaced water dripping out of the bowl and down the drain. Most people don't ever realize that that is happening. They assume that the water level in the bowl will just rise. It might for a second, then it will settle and flow out. It only takes a tiny drip from the tank into the bowl for the bowl to then overflow and have a tiny drip down the drain.

    From your description, it also sounds like maybe you should make sure that the fill valve is shutting off (after you have fixed the flapper problem). If the water level overflows into the overflow riser, then you either need to adjust the fill valve water level (most likely) or replace it. A good replacement is the Korky 528 (white cap) fill valve or, to save some water, the Korky 528MP fill valve, on which you can adjust the amount of water that is diverted to bowl refill. Each would take no more than 10 minutes to install with no tools (except maybe a wrench to get the old one off) and should cost around $10. The Korky 528 valves can replace almost any fill valve in any toilet (except some real exotic ones). If you have a float and ballcock, for example, this little self-contained thing replaces the whole ballcock assembly neatly and in much less space. Video on how to install them here:[video=youtube;Gw7HvHtaA84]http://www.youtube.com/watch?v=Gw7HvHtaA84[/video]



    Good luck!!
    Last edited: Sep 23, 2013
  11. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    Thanks wjcandee for the great advice and excellent description of why water from the bowl would leak into the trapway and down the drain.

    I'm going to Lowe's tomorrow to get some other stuff, while I'm there I'll return the Fluid Master and get a Korky. I like that its made in the U.S.A. I guess I just trust the quality more of something manufactured in the U.S. versus Mexico. When I bought the Fluid Master flapper I just assumed all the brands were made in China.
  12. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas

    update 09/25:

    Replaced the flapper which fixed the water leak from tank to toilet problem. Confirmed this by applying the red food coloring test. Not one drop of food coloring from tank to bowl.

    As for the "dripping" sound from behind wall, the behavior has changed. Now, after a flush I can hear a fast dripping sound (with and without my ear to the wall) for the first minute to two minutes, then it slows to about one drip per second up to about three or four minutes. After four to five minutes the dripping sound seems to have completely stopped (although sometimes I think I hear a drop afterwards but it could just be normal plumbing sounds). I actually timed the dripping sound with a stop watch over several flushes.

    So this is different than before I replaced the flapper. Before the flapper was replaced the dripping sound was constant and would never stop as long as the water was turned on to the toilet.

    The water does not overflow into the overflow riser, but it comes right up to the top where literally another millimeter or two it would overflow into it.

    Is it normal after a flush for water to drip from the bowl into the drain pipe for a few minutes afterwards?

    One side note is that it is possible I am hearing something which most people don't notice because I have extraordinary hearing ability in my left ear (my right ear is deaf and the left ear has over compensated over time. Audiologists love me because hearing tests for my left ear are literally off the charts, especially in high frequencies.)

    Having said that, I don't hear the "dripping" sound after a flush from the other two toilets in the house, one upstairs the other downstairs.

    At the moment I have the water turned off to that bathroom out of an abundance of caution. One question that I have is will the fact that the water is shut off to the upstairs bathroom cause unbalanced water pressure in the plumbing which could cause a pipe to leak or break? Especially when doing something like washing clothes in the upstairs washer?
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    It's normal for water to take awhile to seek its own level in the bowl especially if it's windy or you are using other things that use that drain line (the pressure changes can cause the water to rock a bit). The water in the bowl will eventually stabilize. It is a bowl filled to the brim (called the weir), and even just the act of the water warming to room temperature will cause it to expand a bit and therefore overflow. Now that you've stopped the leak, it sounds like all's well.

    If you have a water hammer (quick acting valves like the WM, icemaker, some toilet valves, etc.) that can cause some pressure spikes in the piping. It's best to deal with them. THey become worse when your pressure is high. But, normal piping should be good to higher than those spikes...rubber hoses on things like the WM may eventually have issues, which is one reason why it's a good idea to shut their supply off when not actually doing laundry.
    Last edited: Sep 25, 2013
  14. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    Ok thanks Jim. I didn't know that about WM / water hammer pressure spikes. I'll turn off the water supply to the WM when I'm not using it.

    Thanks all who replied to the post.
  15. Reach4

    Reach4 Well-Known Member

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    2,648
    Location:
    IL
    It took me a while to figure out that WM is Washing Machine. If you are not using the WM, it will not cause pressure spikes, even if the water supply to it is not turned off.

    I would be shocked if a home refrigerator ice machine could cause much of a water hammer pressure spike (due to the low flow).

    That is not normal. It seems too much of a coincidence that you have the sounds and the high water level. I would reduce the water level in the tank a bit by adjusting the fill valve float.
    Last edited: Sep 26, 2013
  16. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,262
    Location:
    New England
    It's not a bad idea to add some water hammer arrestors at your WM. They're readily available as a no tool solution at most any big box store or hardware store. Sioux Chief and Watts and probably others make them. Get one that has the hose connections already on it, and it's just - unscrew the existing hose, screw on the hammer arrestor, reattach the hose. The safest thing to do is to always shut the water off to the WM when not in use...after all, those rubber hoses may eventually break.

    Any quick-acting valve can cause a water hammer, but the larger the supply, the more noticeable it usually is. It depends on your water pressure, the actual speed of the valve closing, and how well attached the pipes/hoses are (some hoses will stretch, absorbing some of the spike, but that adds stress to them). If you ever look at the hoses to the WM when it turns the water off and you see the hose jump, an arrestor is a good thing.
  17. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas
    Good idea. I'll adjust the fill valve float down a bit.
  18. 702jerry

    702jerry New Member

    Messages:
    11
    Location:
    las vegas

    Thanks for the advice. I'll look into water hammer arrestors. There's a Lowes right down the street from me. I'm sure they will have them.
  19. Terry

    Terry Administrator Staff Member

    Messages:
    15,295
    Location:
    Bothell, Washington
    Really?
    The plumbing code is not shocked by it though.
    In a closed system, hammer arrestors need to be placed on all quick closing valves.
    Washer
    Dishwasher
    Icemaker

    The toilet tank lever should be about 1/2" from the top of the overflow.
  20. Reach4

    Reach4 Well-Known Member

    Messages:
    2,648
    Location:
    IL
    OK... I am shocked. Have you seen a case where a home ice maker (1/4 inch tubing I presume) was actually making noticeable water hammer?
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