Tankless water heater condensate drainage problem

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Wood family, Mar 9, 2018.

  1. Wood family

    Wood family New Member

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    Mar 9, 2018
    Location:
    Fort Mill SC
    We had rinnai ruc90in tankless water heater installed and plumber for not account for condensate drainage. We got an error code and noticed it was leaking out the black cap. So we call and they say they don't handle condensate that's the HVAC guys. But they will do it. So they come out and do this. Problem is the condensate drip is so slow it does not push the water through the p trap. It's this application look correct? The water just sits in the p trap and leaks out It's not strong enough pressure to push it through to drain. What is typical installation? I feel like the plumber that installed this is not very familiar with tankless heaters. Thank you
     

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  2. Ladiesman217

    Ladiesman217 Member

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    Dec 31, 2010
    Location:
    MA
    Bad installation. The entrance of the P trap is below the level of the drain pipe. Water does not flow uphill. Who installed that P trap?

    You have to add an extension to that P trap to make the drain entrance level higher than the drain pipe. Remove the plastic condensate drain hose from the P trap and temporarily let it drain into a pan or similar.

    You also need an air gap between that plastic condensate drain hose and the P trap.


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    Last edited: Mar 9, 2018
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  4. Wood family

    Wood family New Member

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    Thank you! I'm so upset by this work. I do remember them saying this was the highest the trap could go because of all the other piping under the water heater. Do that mean that maybe the whole thing just needs to be cut off at the drain pipe and lowered a bit?
     
  5. Terry

    Terry Administrator Staff Member

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    Everything about that drain is wrong.
    They have a check valve just before the pipe goes down. That is only used on pumped waste, not a gravity drain.

    The standpipe needs to be higher than the drain line, and the p-trap needs a vent. An AAV would work for that. I would love to see pictures of how they ran the venting on top. I doubt that they have ever read a code book.

    The relief line was never run also. That terminates 6" above the ground.
     
    Last edited: Mar 9, 2018
  6. Ladiesman217

    Ladiesman217 Member

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    MA
    The T&P relief valve out needs to terminate about 6" above the floor in my area.
     
  7. Ladiesman217

    Ladiesman217 Member

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    You should be upset. I would cut off the pipe at the P trap and extend everything to the right far enough to clear the plumbing. Then a standpipe extension can be added to the P trap to get it at a proper level. You still need an air gap.

    Did a real plumber do that installation?

    Anyhow, temporarily pull that condensate drain tube out of the P trap and let it drain. Then see if the water heater trouble code goes away.
     
  8. Terry

    Terry Administrator Staff Member

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    Occupation:
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    Location:
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    Nothing will drain past the check valve.

    [​IMG]

    [​IMG]

    This fitting goes on a pump.
     
  9. Wood family

    Wood family New Member

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    Fort Mill SC
    This work was performed by the main plumber's assistant. But they are a licensed company. So I didn't even know about the t&p relief line. When you say terminate 6" above floor do you mean it can connect into these pipes or where would it discharge to?
     
  10. Wood family

    Wood family New Member

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    Fort Mill SC
    They told me I needed that black thing so that sewage back up from the septic did not come into the pipes and have it flowing in the proper direction??? I'm clueless but I wasted so much money on this that I'd like them to get it right but now I'm not sure if I should just start over with new plumber.
     
  11. Ladiesman217

    Ladiesman217 Member

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    Location:
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    You just need to add a T & P valve overflow pipe that terminates about 6" or so above the floor. I keep a small pail under my overflow pipe. I do have a tankless water heater.

    These pictures give you the general idea.


    [​IMG]


    I[​IMG]
     
    Last edited: Mar 10, 2018
  12. Ladiesman217

    Ladiesman217 Member

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    I would leave it in if that is what they recommended to prevent sewage backflow.

    I would insist that they correct that P trap installation. Send the master plumber a picture via email. The "assistant" screwed up. Maybe send the master plumber a link to this thread.

    Does the water heater work now with no trouble codes? I would keep that condensate tube out of the P trap until it is installed per code.
     
  13. Michael Young

    Michael Young Active Member

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    Sep 20, 2016
    Location:
    North Carolina
    Just get some flexible tubing and stick it on the condensate port on your water heater. Buy one of these, and use a bushing to make it fit the current standpipe (need trap). Use a barbed adapter (threaded one side, barbed on the other). stick the other end of your flex pipe on that. bam. done

    If you don't want to screw with, just glue a 12" piece of pipe into that trap. Drill holes in the top 6" of that pipe. stick the tube into the pipe - only 4" into the riser. The holes you drilled in the pipe will create a 6" air gap. that why I said to cut your riser at about 4" lower than the top of the drilled pipe. Easiest fix.

    yes, there are some other issues. But make this small mod and you're golden.

    upload_2018-3-10_10-52-58.png
     
    Last edited: Mar 10, 2018
  14. Michael Young

    Michael Young Active Member

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    Location:
    North Carolina
    I'd like to see more pics of the entire installation. I'm particular concerned about the venting. How did this kid vent this tankless? How did he handle the gas lines. There are issues FAR MORE SERIOUS than a little drip from a condensation port
     
  15. craigpump

    craigpump In the Trades

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    Your plumber is a moron
     
  16. Wood family

    Wood family New Member

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    Thank you everyone for the help. The master plumber is supposed to come out Monday to fix it. Ill update then the repairs!
     
  17. Wood family

    Wood family New Member

    Joined:
    Mar 9, 2018
    Location:
    Fort Mill SC
    IMG_20180312_133233180.jpg
     

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  18. Terry

    Terry Administrator Staff Member

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    Occupation:
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    Location:
    Bothell, Washington
    Why is there a check valve on the trap arm? That is only for a pump.

    [​IMG]
     
  19. Reach4

    Reach4 Well-Known Member

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    Location:
    IL
    That looks much nicer than what I had in mind.
     

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