sudden toilet refill

[q0987]

hello all,

We have experienced this issue for quite some time.
Here is the issue:

One of my toilets will suddenly start to refill the tank and I can clearly see water come out through the inner wall of the lower bowl. Then after 10 sec, it stops. Nothing bad happens. But just want to know what really happens?

Thank you

 

[phishfood]

It sounds as though water is leaking by either the flapper or the flush valve. Once the water level drops far enough, the fill valve turns on and refills the tank. The flow from the rim is a normal part of the refill cycle.

 

[q0987]

It sounds as though water is leaking by either the flapper or the flush valve. Once the water level drops far enough, the fill valve turns on and refills the tank. The flow from the rim is a normal part of the refill cycle.

Hello phishfood,

How do I check which one is leaking?

Also how do I fix the issue?

Thank you

 

[stevemachine]

I would replace the flapper first off. There quite easy to replace. Usually two ears pop off the flush valve unless its one of those lovely american standard old school flappers then it a bit trickier. Google it if anything. Then toss some food colouring in the tank once the tank is full o water again, swirl it around gently (after new flapper is in) let it set 15-30 min and if you see colour in the bowl then you know it's your flush valve leaking which requires removal of the tank and you spin the big nut off that the gasket sits on and pull the assembly out and replace it.

 

[Caduceus]

First, be sure that when the water stops filling, the level is about 1" below the top of the overflow tube inside the toilet and not so high that it is slowly leaking into the overflow. That would require an adjustment on the fill valve.
If that is okay, find a comparable flapper replacement for your brand of toilet at a hardware store or big-box store (Home Depot, Lowes, etc.).
At this point, it's a process of elimination. While at the store for the flapper. Buy a few dye tabs. They will be in the toilet repair section, too.
Replace the flapper, let the tank fill and put in the dye tabs. Let the tabs dissolve and do not flush. This may take some time and, as always, read directions provided.
If the flapper was the correct replacement and you can see dye running into the toilet bowl, you may have a leaking flush valve.

 

[Caduceus]

Sorry, Steve. Was typing as you were posting.

 

[stevemachine]

Sorry, Steve. Was typing as you were posting.

Haha no worries. It confirms that my theory was right, plus you added that the tank level must be below the overflow tube which i forgot to mention

 

[q0987]

My toilet uses fluidmaster 400. I used the flapper valve in the leaking toilet and installed it in another toilet which is not leaking. The other toilet doesn't leak. So I assume the flapper valve is fine. I didn't try the other way but will try it tomorrow.

Also I can clearly hear the water sound after turning off the water input.

So where is my leak?

Assume the leaking is from the fill valve.
Then after I turn off water source with tank full of water, how can I still hear the water leaking?