Changing to a flush valve toilet

I'm trying to cheaply replace a basement bathroom's floor-mounted, wall-outlet toilet, but everywhere I ask tells me it is a special order that will cost upwards of $700 with a 4-6 week lead time. SO, in the interest of saving time and money, I'm considering switching to a commercial toilet with a flush valve (ie. no tank).

My question is: How hard is it to plumb in a flush valve toilet? Do I just have to reroute the water supply from the existing tank shut-off valve to where the flush valve requires it? Or is larger pipe needed?

Second question: There's a jog in the wall behind the toilet (ie. a shelf). Can you usually extend the piece of pipe that goes from the flush valve to the wall? Would that be a problem?

Peter

Flushometer valves typically spec a 1" water supply line. It's not that they need any higher pressure than you have available, but they need a very high instantaneous GPM. So, it may not work.

That's a lot more than I've been selling the Gerber floor mounted rear outlet toilet for, model 21-310, $399.00
Or the American Standard Yorkville for $499.00
These models use a Flushmate, and work with a 1/2" water supply.

Takes me a couple of days to get these in the Seattle area.

A commercial flushometer, with the 1" supply would need a new water meter, water service, and repiped 1" line to the toilet.
Not a cheap way to go.

specialist

There is also the Crane 3386 "Economiser".
http://www.craneplumbing.com/products/Default.aspx?prodNo=3836&lang=EN

American Standard Flemington?

Terry's report on "best low flush toilet" does not mention the American Standard Flemmington, which is only one of a few options for those of us with back outlet toilets. I've read that it is tricky to install, but nothing about its performance.

The other options I have are Kohler Barrington, which is not comfort height, and Duravit Starck, but I can't find reviews on them and am leery about installing something behind the tile that isn't "proven."

I don't know whether the Gerber rear exit comfort height has the problems being reported elsewhere on this site but that high a failure rate has pretty much put me off than brand.

Suggestions?

An expansion tank could be plumbed in to get that "very high instantaneous GPM" without upsizing the houses water service. Pretty much that would be kinda like making a home made pressure assist toilet.

Whenever I see "home made" and "toilet" in the same sentence, I worry...

An expansion tank could be plumbed in to get that "very high instantaneous GPM" without upsizing the houses water service. Pretty much that would be kinda like making a home made pressure assist toilet.

Click to expand...

You could pipe a one inch supply from an expansion tank.

So what looks better, an expansion tank in the room, or an enclosed tank using a Flushmate.
If it's about looks, being more commerical looking, you would need a place to set the expansion tank.
And it would need to be an expansion tank with 1" threads.