Is there a standard height for a flush tank relative to a toilet bowl?

In most cases the height seems to be defined by the position of the water outlet from the cistern. Are the cisterns ones actually recommended by Toto? Is the flush volume set to the recommended value for the Toto WC? If they have a low flush option, don't expect it to do much except introduce some water into the bowl, only go by the full flush behaviour.

Toto visited and had no adverse comments about the types or sizes of the cisterns but only their mounting heights. The insides the bowls have two water jets, one at low level and one just below the rims. The vast majority of the water comes through the lower ports and so leaves too little for the higher level flow to wet the inside surfaces of the bowls.

I'd say Toto's fault for not specifying a height requirement.

"What is a joist"? (Peter Hucker)

Cisterns are normally mounted only a few cm above the toilet, so if Toto have different requirements from UK standards they really ought to specify them. Indeed, any cisterns I've seen would need modifying to achieve a higher level. You mentioned wall mounting frames. Do you have access to any drawings of these, which might give you some clue as to whether Toto are telling the truth or not?

Two sets of water jets suggests two paths for water to take within the structure, or externally. Has the path to the upper jets become blocked with debris or packing that the plumber omitted to clear out?

That sounds like either the flow rate over the duration is too low, or the bore of the pipework to the lower flush holes is too big relative to the top ones. Give me an old fashioned unit every time. I remember a plumber joking or was he, to me that cistern heights need to be about 1 foot higher than manufacturers suggest to work properly. :-) Brian

"Anthony R. Gold" wrote in news: snipped-for-privacy@4ax.com:

Lots of stuff on the internet if you Google it. Is the outlet working as it should? Even YouTube videos.

are their ANY wothwhile standards left? ......

in scotland 130 years ago you had to screw the pan down with four brass screws ......

otherwise it got nicked?

in the common stair head cludgy probably ....

Yes, there are two water internal paths from one common entry port, so there is no ability to reduce one in order to better balance their flows rates. Two of these toilets are performing poorly and no internal debris has been found. My guess would be a poor design except only that this is a well respected brand and also I do not see the clamouring of complaints that I would have expected to find if a defective design or manufacture was the issue.

You say that Toto say that the cistern isn't high enough.

Leaving aside the lack of documentation, why not just move the cistern higher?

From your description of the design it seems entirely reasonable that it relies on enough head of water to produce a flow that maxes out the lower waterway and forces water through the upper waterway.

There must be a logical minimum flow rate for the design to work.

What exactly is the aim of the question?

Are you looking for a reason to sue Toto for the cost of having the cisterns raised?

If so uk.legal.moderated is possibly a more suitable NG.

Cheers

Dave R

....a high level cystern with a three gallon flush....none of this pussy southern stuff ...

The cabinetry will not allow that.

At the point of sale the supplier was asked whether these toilets required any particular tanks or installation had replied that any good quality tanks would work fine. So a guess that you find entirely reasonable and logical is neither documented by Toto nor known in their supply chain.

To discover if there are standards or conventions that my builder violated and maybe hear of any good or bad experiences with these particular toilets or with Toto products in general from other subscribers to this ng.

No.

Plan B may be these:

Does anyone have any positive or negative experiences or knowledge about them? BTW the site is supplied by water at good flow rate and pressure (3.5 bar) and so complies with the manufacturer's rather demanding requirements.