Toilet keeps flushing

[july3feb2]

Hi everybody. I found this site while attempting to find something besides "change the flapper" advice.
Here's what's happening:
My toilet flushes fine. Tank fills. Within a minute or two water (about an inch) leaves tank somehow and then the tank refills again.
I have changed the flapper. Chain not getting caught...can't figure out the problem.
While reading about flush valves/fill valves etc I realized that all the advice and pics are different than my toilet set-up. My house was built 6 years ago in Ontario, Canada. The black refill line is very short and attached to a clear water line that goes into the fill valve. This clear water line is also connected to a clear water line with a brass elbow that goes out the top of the toilet tank and down into the floor (presumably somewhere in the basement. The other toilets in my house (as well as online) all have a short refill line clipped to the top of the valve and no elbow/extra clear water line.
We have no leaking anywhere from the toilet itself and it is only the past month that our water usage has spiked suggesting some sort of leak. I am fairly certain this toilet is the culprit as the refilling tank/phantom flush seems to be a new issue.
Hoping this all makes sense and somebody on here can help me out.
I think I can change the flush valve and fill valve on my own if necessary but now I am trying to figure out what this other water line is.
Thanks in advance.
ps. I realize I may be getting the fill and flush valve terminology confused in this post. Hope you can figure it out

 

[Reach4]

Turn off the water with the stop valve. How far does the water in the tank drop?

 

[Sponsor]

 

[WJcandee]

If it shuts off and the water then drops an inch and it then refills, causing another flush, there's a leak or a siphon. Most probably a leak, and most probably past whatever kind of flapper or other device drains the water from the tank. The reason it is "flushing" is because enough water is entering the bowl to raise its level high enough to cause a siphon that clears the bowl.

At some level, most toilets are the same. You have a vessel that holds water and releases it on command through one (flush) valve, and then brings water back into that vessel through another (fill) valve. When the water that leaves the tank raises the level in the bowl high enough (fast enough), it causes a siphon that sucks the contents of the bowl from the bowl. While the tank is refilling, some of the clear water is diverted into the bowl to refill it as well.

It sounds to me like whatever should be keeping the water in the tank isn't doing its job, whether it's a flapper or otherwise. The fill valve then opens to raise the water in the tank to the proper level for the next flush.

If you can shoot us a photo (it's easy to upload here), or post a video to Youtube and then link us (also easy), we would have a better idea of what he innards of your toilet look like and it would be easier to help.

Or tell us the toilet make and model and we can look it up.

We're here to help.

 

[july3feb2]

Above are two pictures. In the 1st you can see the extra water line attached to the refill hose. No idea what it's purpose is. The 2nd shows how long the refill hose is that is inserted in flush valve. It has always been in there. Toilet is 6 years old and only now are we experiencing problems so not sure the hose is the issue just noting that it is very different from all the pics I can find when searching for a solution to the problem.

There is residual blue ink from a dye test I did. The dye NEVER entered the bowl. I have changed the flapper anyway but still experiencing the phantom flush. You will see on the right side of the tank two small pen lines. When the toilet is flushed manually the water level goes to the top pen line. Within a minute or two it lowers to 2nd pen line and the fill valve kicks in, releasing water back into tank.

Any advice/suggestions would be greatly appreciated. Would love to know purpose of that water line going out back of toilet and into the floor also.

 

[Terry]

The fill valve needs to daylight above the overflow tube, or it will siphon water out of the tank.

I have not seen a second line out of the tank like that. I wonder if it's for a floor drain.

 

[Jadnashua]

I think Terry's probably right...the second line is being used as a trap primer. And, as he said, the hose going into the overflow cannot be lower than the top. Having the other hose off the tee going down could also create a siphon. I may not have done it previously, but I'd suggest that the seal may be shot after 6-years. That looks like a Fluidmaster, and the seal is easily replaced without tools for a few dollars. In theory, it's not supposed to siphon, but all bets are off if the seal is worn or shot.

 

[WJcandee]

Well that trap primer dropping a full floor below is an enormous siphon. The siphon would be broken if air was being sucked through the hose going into the overflow, but likely it isn't, particularly if the other end of the trap primer is sitting in water, which I will bet that it is. If you can find the other end, and it's a floor drain in the basement or something, you can disconnect the whole contraption and just make sure that you don't let the trap in the basement floor drain run dry. Pour a few cups of water into it occasionally, and it should be fine. Also, as Jim suggests, just replace the cap on the Fluidmaster, or buy a Korky 528MP fill valve, which in the future also has a cheap-cap that has all the moving parts in it.

Oh, and remove the contraption and just set up the refill the way it is on the other toilets.

 

[WJcandee]

In theory, it's not supposed to siphon, but all bets are off if the seal is worn or shot.

True, but the "anti-siphon" being referred to on the fill valve (and in the code mandating its use) is a different siphon entirely (as I'm sure you know). Manufacturers constantly remind folks that the potentiality of a siphon through the refill hose is a real possibility.