Mansfield toilet tank overflow causing leak downstairs

[Aaron Perez]

Hi all,

I have a 2 story house. Had a water leak a few days ago from somewhere on the wall between the laundry room and bathroom. Laundry side has water connection, bathroom side has no water (toilet/sink/shower/tub water sources are on outside wall). Figured it was washing machine's drain piping, but that looked fine. My wife checked bathroom directly above, said that water in the bowl was swirling, but no one had recently used it. She used the toilet and after flushing/filling, no continued filling or swirling.

Yesterday had another leak. No one ran any laundry that do, so unlikely to be any water source from downstairs. Checked toilet upstairs and found the culprit: water in bowl swirling, could hear it filling, pulled tank lid and saw water going over overflow tube. I have since adjusted the fill level but will likely replace the tank internals.

So, question, finally ... life story, I know, but anyway ... what could cause a 2nd floor toilet's continually properly draining overflow tube to leak into the walls? We've been in the house for 2 years and haven't seen any leaks in normal usage until this overflow issue. The toilet never overflowed outside the toilet (no water on 2nd floor). The house was built 2001, not sure if toilets are original but likely. Also, if it matters, toilets are Mansfield.

Just not sure if I have a bigger problem lurking in my walls that I should be getting fixed before it's a serious problem.

 

[Jadnashua]

Sometimes, there's a notch or something else and if the water level gets too high, it can leak out there.

But, when the water exceeds the proper height in the tank after it had been working, the seal in the fill valve either needs to be replaced (easy on some, not possible on others, a picture would help), or the whole fill valve needs to be replaced.

Unless the water level is so high it can leak out the low point on the tank rim, there's something else wrong.

In the interim, shut the water off to that toilet. Once you figure out what type of fill valve it is, you'll know if it's repairable (Korky and Fluidmster are both easy to fix with no tools required).

 

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[Helper Dave]

The only connection I can imagine (since the overflow simply lets water into the bowl), is that the wax seal is broken, the pipe is cracked somewhere under the floor or in the wall, or a joint is leaking. Water constantly going down the toilet could just be exposing the problem.

Investigate a little more, though. Where exactly is the water damage underneath? Do you have any access to see any of the pipe, or can you make access where it's wet to take a look up in there? When you flush the toilet, does it leak more?

Of course, it might not even be the toilet. The laundry trap could be leaking, or a vent pipe. What's all above the spot with the water damage? Cutting walls, or ceiling apart to find out might suck, but letting the water damage continue is the worse option.

 

[Jadnashua]

Water will flow along the path of least resistance...it can go a long ways, so where you see it, isn't always the source.