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Rinnai error code 25

hags428hags428 Member Posts: 2
I have a recently installed Rinnai PUC 98. After a few hours of use I the water goes cold and I get a error 25. This error is a condensate trap full, I believe. I have a condensation tube going to a pump that is also used for my furnace/ac. Once the error comes on, I go down stairs with a bucket and disconnect the tube and water comes out. Once this is done the water heater works properly. It seems like it doesn't want to drain through the tube because of a pressure issue or air in the line.


  • Tom_133Tom_133 Member Posts: 671
    Do you have a vent in the condensate line at all? I have seen this once where someone just ran a line from the condensate trap to a pump but didn't include a wye or tee in the line so it couldn't drain. If there is no vent I would add one, if this has been running normal for a year and just started in then the sensor in the condensate trap could be suspect. I know you said "recently" but not sure if thats a week ago or a year.
    Montpelier Vt
  • hags428hags428 Member Posts: 2
    What is the purpose for the wye or tee? It was put in two weeks ago.
  • EricAuneEricAune Member Posts: 432
    edited May 2016
    Consider the condensate drain tubing without a "vent" to be a drinking straw full of liquid and you've got your finger on the upper end. Once you take your finger off then the liquid runs out.

    I've seen this a few times with condensing equipment. A tee fitting on the vertical tubing with a short piece of tubing directly into a 90 degree elbow, another piece of tubing positioned vertically a few inches in length should take care of it. I offer this as a fix considering the age of the install, the condensate pump is less likely to be the problem although it could be the pump float sensor as well.

    One other possible problem is if the installer double trapped the condensate from the unit. I'm not familiar with the model listed but it likely has its own condensate trap, in this case there should not be an external trap installed in the piping. External traps can be made with fittings or an actual p-trap made of the same tubing material as the drain tubing. Hope this helps.
    "If you don't like change, your going to like irrelevance even less"
  • JackJack Member Posts: 1,044
    That unit is internally trapped on the condensate side. Cut your drain line below the unit and provide an air gap or provide the air gap at the condensate pump.
  • lchmblchmb Member Posts: 2,975
    ya know..I read this...knew exactly what it was supposed to be and did it wrong on an install....smacked myself when I went back to fix it..I looked awful funny with egg on my face..
  • Tom_133Tom_133 Member Posts: 671
    Ichmb, ask me how I knew what it was right away!! I blew it too. 1 hour from my house one way to make a 5 minute repair.
    Montpelier Vt
  • chileebchileeb Member Posts: 1
    Are there any visible directions? I have a Rinnai Model RC80HP with that same code 25. My husband has passed and I don't know how to fix it. Any directions that I could look at to fix it myself?
  • Leon82Leon82 Member Posts: 654
    what does it drain into?

    try to adjust the hose and make sure its not under water.

    how it it connected to the heater?
  • lchmblchmb Member Posts: 2,975 check page 22 it show's where the condensate drain plug is located on your unit. If the pipe is directly connected to that, remove it and allow the water to drain out. If there is a space between it and the catch pipe then you may have an issue with the internal trap itself (may be clogged)
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