Gerber Rear Outlets Maxwell and Ultra Flush

[Cracked]

Hello,

First, I'd like to say thank you so much for having this great plumbing forum for all.
I've read a lot here that has been very helpful.

I actually have 5 questions, so I'll start with the easiest first.

1. Condo- Rear outlet- I understand the flange standard is vertical 4"o.c. with up to a 1/16" variable, so why are toilet specs saying 4.25"rough in?

Reference: in place - Gerber Aqua Saver, 2" gravity fill valve, concealed trap-way, EL bowl, 30.25" depth, next to 31" handicap rail attached in tile floor. While cleaning the tank I discovered a 4" black crack along the bottom back. Suspect it would be smart to replace now that I've seen the warning. I'd replace only the 3.5gal tank if I could find a white one that would work with it.

Desire: Gerber, 1.6gpf, 3" fill valve (gravity), 2-3" trap-way, glazed, concealed, EL bowl, ergo ht. doesn't matter either way as we're < 63. Though I suspect ergo ht helps gravity flushing, even if only a little. The bath room is next to the bedroom and there is no insulation in this building.

Maxwell for the most part satisfies the most important specs, excluding the larger, concealed trap-way and 30.5" depth of the Ultra. The larger trap-way is important so that mineral deposits don't reduce performance over time as is the case with current Aqua Saver. Calcium deposits are a constant battle here in Fl. and I can't afford water softner. Concealed trap-way is understood.

2. So, would the Ultra's tank fit a 3" fill valve instead of the assist device?​

I can't find the diameter in Gerber's specs, Flush Mate's, nor anywhere else online.

3. I like the Maxwell. Should I just settle on it though it's shorter bowl depth of 27.5" will look short next to the 31" handicap rail ?

4. I wouldn't mind using a Maxwell tank with a Ultra bowl if they fit?

5. Any suggestions of questions to ask a prospective plumber so that I know they will use the neoprene seal?
​

Asking if they've installed rear outlets before seems pointless, because many will still use a wax seal according to other plumbing forums for plumbers. I didn't see anyone from my area among your resources, but love that you offer that.

The condo assoc. had a plumber here to replace the flange in the wall a few weeks ago and before he got started I asked of his experience with rear outlet toilets and stated that my preference is the rubber seal. He used what he had in the van, a thin wax seal and made sure to take his trash with him and never told me about the wax seal, though I saw the box.

​

Thanks in advance. I know I've asked a lot, but I removed the tank a few weeks ago thinking I would just clean the tank & replace all of the parts and be done.

 

[Terry]

The Gerber with Flushmate tank needs to match with the correct bowl. They do not interchange. Pick the tank you want and get the matching set.
The Flushmate is a pressure assist similar in size to a 2" flush valve but with pressurized water being pushed out and through the trapway.
The Maxwell is a 3" flush valve working with a siphon jet. A totally different kind of flush action.

 

[Sponsor]

 

[Cracked]

Thanks for the confirmation and quick response. As soon as I find a plumber I'll let them know which Maxwell. Any tips for question 5?