Toilet : When idle tank is filling for brief period

[JWBlue]

A toilet in our home has an intermittent noise of water filling the tank. It is the noise when the tank is filling after the toilet if flushed except it is occurring when the toilet is idle. The filling noise lasts for about 2-3 seconds. It happens about every hour.

We have had a plumbing company come out 2 times to attempt to fix the issue. Both fixes lasted short term. I believe, but not certain, the part replaced was the flapper.

If we leave it like this could a bigger issue occur? Should we replace the toilet?

 

[Reach4]

How high is the water level with respect to the overflow tube?

If you turn off the toilet supply valve at the wall, how quickly does the water level drop? If it drops about an inch per hour, that would go along with the idea of a slow leak at the flapper. If the water drops, but stops dropping, then you would look at something other than the flapper.

Commonly this is a leaky flapper. Sometimes you can wipe a bit of debris from the seat that the flapper mates with. Sometimes a softer flapper fixes it. Sometimes the chain that pulls the flapper is a bit tight.

It is not likely to cause a bigger issue.

 

[Sponsor]

 

[hj]

Often the small tube is stuck too far down into the overflow tube and siphons the water out, then the valve has to refill it. Any GOOD plumber should be able to fix the problem in about 2 minutes.

 

[JWBlue]

Doesn't the flapper come attached to the overflow tube unit? I wonder if just the flapper was replaced or if the entire unit was replaced.

 

[Jadnashua]

Every toilet that uses a flapper, the flapper valve is replaceable. Unless the overflow is physically broken, it is not replaced when you need to replace a flapper and should last the life of the toilet.

There are only a few areas when water can leak on the tank:
- under a flapper, but there are numerous reasons which include, a worn one, one installed incorrectly, one that gets caught on something, one where the chain either gets caught underneath or is too tight, and holds it up off of the seat, or crud or a defect in the seat so that the flapper can't seal
- a crack that lets water leak - the overflow is one possibility, but it could be the tank, but you'd notice that on the floor
- a bad or loose joint in the base of the overflow/flapper valve assembly. It might just leak into the bowl, but it could leak onto the floor - fix that usually by tightening up the nut after removing the tank. Normally this only happens on a new one, or after replacement, not some time later
- improperly installed or deteriorated rubber washers on the tank mounting bolts, but there, it usually leaks out on the floor.
- while not technically a 'leak', if your rubber hose is terminated below the water level, it can allow water to siphon.

Then, there's the possibility that the refill valve is not shutting properly, but then, as water rises, it will trickle down the overflow, that won't happen intermittently, it will be constant once it rises enough to reach the overflow.