Heat pump water heater condensate drain and water softener back wash draining into same standpipe?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by tunabreath, Mar 27, 2021.

  1. tunabreath

    tunabreath New Member

    Feb 28, 2019
    Is it permissible to have the condensate drain from a heat pump water heater (5/8" tubing likely) and the back wash waste from the water softener set to discharge into the same trapped standpipe? If so, what size would be required, 1.5"?

    Also, is an air gap fixture needed or could I satisfy air gap requirement by using a funnel drain and having the discharge set 1" or so from the top of funnel drain? I would eliminate the 5/8" tubing and use 3/4" PVC for both the water softener and condensate drain, securely mounting to the foundation wall using a90 deg elbow 1" above the stand pipe or funnel drain.

    Or would my best course be to use two of the air gap fixtures below?


    OR this:

    Last edited: Mar 27, 2021
  2. breplum

    breplum Member

    Oct 2, 2004
    Plumbing and heating contractor
    San Francisco Bay Area
    I would recommend two inch trapped drain with a typical four x two reducer as a funnel. Receptors are always two inch.
    That unit from Supply House looks interesting, but crowded for the two 3/4" drains, esp. a high speed flush from a softener.
    NOTE: I've never worked around water softeners, so not sure what backwash flow is.
    You may be better off with a 12" x 12" receptor.
  3. Sponsor

    Sponsor Paid Advertisement

  4. Jeff H Young

    Jeff H Young In the Trades

    Feb 27, 2020
    if the fitting is an inch above the stand pipe then you have an airgap. a 1 inch airgap is fine. an airgap fitting is not required
Similar Threads: Heat pump
Forum Title Date
Plumbing Forum, Professional & DIY Advice Hybrid (Hear Pump) Water Heater Jun 9, 2021
Plumbing Forum, Professional & DIY Advice Using soft copper in a crawlspace for heat pump water heater Nov 5, 2020
Plumbing Forum, Professional & DIY Advice Watts Recir Pump on DUAL Water Heater in Sequence Sep 21, 2020
Plumbing Forum, Professional & DIY Advice Radiant Heating - Taco Pumps Ran Dry for Few Hours - #30 Pressure Relieve Valve Popping Off Now Nov 28, 2019
Plumbing Forum, Professional & DIY Advice Recirculating pump/system for Rinnai Tankless water heater Nov 28, 2019

Share This Page