What low-flow toilets can be used in back to back installations.

Discussion in 'Toilet Forum discussions' started by hrcohen, Jun 8, 2013.

  1. hrcohen

    hrcohen New Member

    Jun 8, 2013
    I want to replace 2 old back to back toilets which don't flush well with low flow varieties. I'm interested in both the American Standard Champion and the Toto Drake. However, the installation instructions for both of these warn against using them in back to back installations. If I understand correctly, because they both flush with high intensity, there is the possibility that water from the flushing toilet may back up into the other toilet, and also the possibility that water from the non-flushing toilet may be siphoned into the flushing one. The instructions suggest that plumbing codes prohibit use of a cross fitting for the drainage pipes from the 2 toilets, but do allow the use a Y fitting.

    I live on the 4th floor of a condo building in the Chicago area built in 1978. I don't know if it's likely that my building has the allowed type of fittings, so that I could install either of the toilets I prefer, or if I should be considering a different type of toilet. I have found lots of reports on the web of people who have installed both Toto Drake and American Standard Champion in back to back installations and are indeed having the predicted problem. One of the reports actually shows pictures of the drainage pipes which seems to be the Y type, yet they are still having problems.

    Does anyone have any useful insight?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    Almost any of the low-flow toilets will flush fast enough for skipover without the proper fittings.

    Last edited by a moderator: Oct 3, 2013
  3. Sponsor

    Sponsor Paid Advertisement

  4. Gary Swart

    Gary Swart In the Trades

    Sep 1, 2004
    Yakima WA
    Toto Drake instructions for back to back installations require a double sanitary tee-wye fitting.
    Last edited by a moderator: Oct 3, 2013
Similar Threads: low-flow toilets
Forum Title Date
Toilet Forum discussions Low-flow toilets vs septic systems Aug 4, 2016
Toilet Forum discussions PERC study released on drainline carry of solid waste by low-flow toilets Nov 25, 2012
Toilet Forum discussions Long waste line vs. low-flow toilets Mar 18, 2009
Toilet Forum discussions Terry Love's consumer report on low-flow toilets Aug 31, 2004
Toilet Forum discussions Old low-flow toilet won't flush without extra water, SFGate Jun 16, 2011

Share This Page