I think five inches would be fine.
The flush valve can be rotated and lifted out
We have a toilet that we want to replace. It is unfortunately under a sink shelf ... see picture. It is 35.5 inches to the underside of the shelf over the toilet. We want dual-flush and wished to install a Toto Aquia. With the tank lid off, the Aquia measures 29 inches to the top. That would leave 5.5 inches clearance above the tank. Too small to put a head in to look see. There are only 2 units in the tank. It looks like, if needed, they could be removed with that minimal clearance above the tank. Am I being realistic? Would it be wise to purchase the unit with that clearance constraint?
I don't know why you would want to replace a toilet that cannot overflow if it stops up with one that can, but as long as there is room for you to operate the push buttons, that should be your main concern. When it has to be repaired or serviced a way will be devised to do it.
I had the Aquai installed for two years, and Cathy has one, installed two years plus,why you would want to replace a toilet that cannot overflow if it stops up with one that can?
Neither of them have been stopped up.
They have a fairly large trapway.
Bigger than most.
5.5" is plenty of space to work with.
I admit, it's a pretty looking toilet ... BUT,why you would want to replace a toilet that cannot overflow if it stops up with one that can?
1. it stops up with undesirable frequency even after having the plumbing roto-rooted ... we are in a bungalow without a basement.
2. annoyingly often the flapper doesn't close properly ... even after plumber installed a new one. My wife called the plumber because she thought the problem was my ineptness in diagnosing and replacing the flapper.
Can't think of any other good reason.
Thanks for the quick response Terry.