Thud when flushing new Toto toilet

[Jdbs3]

A few years ago I installed a Toto Drake - great toilet. Recently, I installed 2 more Drake's in my house.

Both work fine. However, the one in a power room on the first floor makes a distinctive 'thud' nose when flushed for #1. The noise is coming from the flapper that drops down to allow the tank to re-fill.

The only difference between this toilet and the other 2 is the number of spacers I used between the existing toilet flange and the extender. With the Set-Rite flange extender product, the other 2 toilets, used a 1/4" spacer. For the 'thud' toilet, I had to come up 1" so used multiple spacers to make up this height as per the product.

What might account for this 'thud'? It does not make the noise if I hold down the handle for a full flush.

Thanks

 

[WJcandee]

Well, someone has given you a bum steer on how the toilet works.

IT'S A FULL FLUSH WHEN YOU PUSH THE HANDLE TO THE END OF ITS TRAVEL AND RELEASE. It's NOT A DUAL-FLUSH TOILET. IT WILL FLUSH YOUR POO JUST FINE BY PUSHING FULLY AND RELEASING THE HANDLE. When you hold the handle down, you are using about 3.5 gallons of water, double what is necessary. The toilet is designed to use 1.28 or 1.6 gallons, and it doesn't empty the tank on the flush because it is using the weight of the extra water beyond what it needs in order to add thrust to the flush.

As to your thud, the sound is caused by that extra thrust of the extra water, and exists in one form or another in all Drakes. Why you're hearing it on that one is most likely that toilet is in an area that amplifies the sounds from the toilet tank more. I.e. live walls. Of our several Totos, the one that you can hear a thud with as the flapper snaps closed is also the one that I hear the sounds from the tank more, like refilling. It's under a wall protrusion with hard live surfaces all around, in a small bathroom.

The thud is the sound of the flapper, under the weight of the water that is supposed to remain in the tank, snapping closed against the valve seat on the flush valve. It doesn't thud when you have drained the tank because there is no significant amount of water above it to force it against the flush valve seat.

How you raised or lowered the toilet on installation has nothing to do with whether the flapper will snap shut hard under the weight of the water.

Here's a video of how it should work in the tank. This flush clears mountains of poop without clogging.

And that half-a-tank does this:

 

[Sponsor]

 

[Jadnashua]

Some people go into great detail about how many of the Toto toilets are dual-flush. That is incorrect. While yes, you can get a partial flush if you play with the handle, there is only one way it was designed to work, and that's push down fully, and release. On a dual-flush toilet, the bowl's water volume is smaller than a typical, conventional toilet. That is so that when you do use the smaller flush volume, it still EMPTIES THE WHOLE BOWL RATHER THAN JUST DILUTING IT! On a conventional toilet, while yes, trying to do a partial flush will clear MOST of the bowl, it does NOT clear it all unless you do a 'normal' flush. That functionality might have worked with the older 3.5g or greater volume/flush toilets, but does NOT work with the new, low-flow ones.

Toto tends to use more than one supplier for their toilet fill valves. If that one, noisier toilet is using a different valve, and you have fairly high water pressure, that may be the source of the noise. While flushing, watch the hose going from the shutoff valve to the toilet and see if it jumps when the toilet fills. If so, you have a classic water hammer. You can solve that by replacing the fill valve, or adding a hammer arrester.

 

[Plumbs Away]

It always kills me when I see the YT toilet videos where the DIYers refer to their new "dual flush" installation and demonstrate with the "actuate and release" and "actuate and hold." My 1.28 GPF AquaSource is a single flush and completely clears and cleans the bowl with the intended flush method. It even swirls the water to help keep the bowl clean. Sure, I can hold the flush lever down and empty the tank, but it accomplishes nothing but needlessly wasting water.

 

[Jadnashua]

Some refer to the dual-flush as a flick verses a full depression. Pressing and holding is a big waste of a precious resource, assuming you get a decent toilet - not all work well. As time goes on, more and more of them do, but it is still not a given. Toto seems to have done a good job with their engineering. Unless the toilet has two buttons, or a dual-function lever (some pull up for one function, and down for the other verses having a separate button to activate them), it is NOT dual flush, and you're fooling yourself. Any decent 'normal' toilet will evacuate the bowl fully when flushed in the standard fashion, no flicking or holding required.