Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Rinnai ruc98, intermittent hot water

Hello all. I am new to the forum, stumbled upon it while searching for help. Thanks in advance to all that take time to help out on these forums. I just moved into a new home, new construction . The house is equipped with a rinnai ruc98 water system. Natural gas . It's a single family home . Last night the unit worked great when I had a shower, this am it would only provide about 20 seconds of hot water . The in use light would go out, it would begin to beep and the water temp where it usually says 120 would say 25 . The control panel Is very basic , on/off, priority, up down buttons , and a digital readout . I have a call in to the home builder but while waiting I thought I wouldn't post here also. Thanks everyone .


  • lchmb
    lchmb Member Posts: 2,997
    sounds like error code 25 which is blocked condensate. (this is getting to be a normal one) check the condensate line on the back left of the unit to make sure it is open and draining. Should be in the manual for the unit. The condensate drain line cannot be attached directly to this port it must have an air space...and the port open...
  • flatjay356
    flatjay356 Member Posts: 2
    I owe you big time ! Now my wife and daughter can have their hot showers tonight ! The clear tube off of that port had a few loops in it, taped together, and some water pooled . The tube is directly off of that port and goes into a drain. I just took the loops out so it has a straight run into the drain now . Not sure if this is exactly how the install should have been but for now it's working . Thanks again for your help , we all really appreciate it .