My parents are having this problem whenever they flush the toilet: when the tank is just about done filling the feed pipes rumble until they run some water somewhere else, then it stops.

They just changed the innards a few weeks ago and this started shortly thereafter. I vaguely recall seeing this same thing on Ask This Old House and I think it's something to do with an adjustment on the fill valve. Is this ringing any bells with anyone? I'd rather know exactly what I'm looking for before I go mucking around and just poking at it.

Thanks!

Greg

It's almost 50/50 whether the noise is generating from the fill valve in the toilet tank, or the shutoff valve that supplies the toilet tank. I would guess it's the shutoff valve. TURN OFF THE MAIN WATER SUPPLY TO THE HOUSE, then turn on a cold faucet on the floor below the offending toilet (to drain water out of the pipe). Leave that faucet in the on position. Flush the toilet, put a towel under the valve, and you're ready to start.
You see the handle, it is attached to the valve stem. As you slip your hand over the handle and along the stem you get to a "nut" that the stem goes through. That is the "packing nut" you must loosen. Unscrew the nut until it is just hanging on the stem. Then, by holding the handle, unscrew the valve stem out of the valve body. You should have it in your hand. Is there a rubber washer on the end? Remove it (it just pulls off) then reassemble the valve without the washer. Tighten the packing nut. Go turn the main water back on, remember to turn off the faucet you turned on earlier. If that washer was the problem, the noise will go away. If it still rumbles than you need a new fill valve in the toilet tank. Good luck.

It is usually the fill valve itself as it starts to close. When you open another faucet, the pressure drops so the fill valve can close, but it does not open again when the pressure is restored, otherwise the sound would start up again. They either have a defective fill valve, or a cheap one.

It's a special-order part because it's a specialized, compact, one-piece toilet. For what they paid for the parts I should HOPE that they're at least helf-way decent. Still, they did say that they just changed it all out and the problem start not long after.

Jerco suggested the shutoff valve and fixing THAT will be a chore because this toilet is LOW and the tank rests right against the valve (presumably at, or close to, full open).

I wrote all that and then just went up to check it again. I had the tank lid off and it didn't do it. There was also a little water on TOP of the fill valve. That shouldn't be there, should it?

I was thinking that maybe the float-arm-hinge is hitting the tank lid?

Water on top of the valve is not always unusual with those toilets. What brand is it? Case, Briggs, American Standard, Kohler, or...? Is it a rumbling or bubbling noise? A bubbling noise is common, and natural, with that type of toilet just before it shuts off.



Edited 2 times.

Seriously, take that washer out of the valve. At least it will eliminate that as THE cause. If the tank is pressed up against it, just remove the handle first. It could be in a half closed situation (or is that half open?) for all we know. Give it a try.

no matter what brand there is always a chance of bad new parts.

it is either the stop or the fill valve.

- - - - - - -

PLUMBERS "Protecting The Health Of The Nation"

The toilet is from Sears. The only markings I can see are inside the tank and it says Sears and a model number and that's about it.

It looked like maybe it was the float-arm hitting the tank lid because it never seemed to do it when the lid was off. So I stuck some spacers in there and it worked!... for the first flush or two.

So NOW I'm thinking it's one of a few things: bad fill valve, Jerco's washer, **OR** the shutoff valve is NOT at full open and the new fill valve is not getting enough pressure to function properly.

Is this the same thing as "hammer" ?

I always think of water hammering as a quick rumbling that stops on it's own. This keeps going! I let it go once for about 15 seconds before I couldn't take it anymore and had to run some water to stop it!