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Rinnai RC 98H

Good Morning. Looking for help regarding our system which seems to run fine in the mild temperatures however over the past 2 years we have had issues with a code 11 and code 10. We have infloor heating in our finished basement as well. We have had the whole unit taken apart and cleaned x 2. Once last February and again yesterday. The unit ran fine for the first 3 years with no issues at all. Not sure what to do next. I believe the gas line is 3/4". Thanks for any help or suggestions.


  • lchmb
    lchmb Member Posts: 2,997
    Did he clean and Ohm out the burner sensor and flame sensor?
  • kcopp
    kcopp Member Posts: 4,440
    So this is a tankless water heater being used to heat a house?
  • Andreb
    Andreb Member Posts: 2
    He totally took it apart. He did not clean flame sensor. He cleaned the manifold. Not sure what Ohm means? There was a small amount of hard water deposit on compartment above which he cleaned. It worked for most of yesterday until the temperature dropped below zero. Then after my wife showered it triggered a code 11.
    It is a tankless hot water heater with a storage tank. Secondary heat (radiant heating in basement floor).
  • Jack
    Jack Member Posts: 1,047
    This is just a guess as I have no idea how the system is set up or piped. 11 means the unit tried to fire and could/did not. 10 says that the inducer fan saw some irregularity. Describe the venting system lay-out and confirm dip switch settings.
    I don't like them for space heating as a rule. I've seen them short cycle in closed loop heating applications and it just beats the hell out them. Again I do not know how your system is set-up, but with a combination system I think you will need a tech on the 800 line to Rinnai tech service. Number is on the side of the unit.