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Rinnai tankless woes



  • Jack
    Jack Member Posts: 1,047
    The turbine "in" the cold water inlet valve

    Is the likely culprit. If the turbine turns and the unit will not fire then the unit would code out 11, tried to fire and failed. Either the turbine is stuck or the flow control unit is bad.
  • JZZH
    JZZH Member Posts: 11
    Re: The turbine "in" the cold water inlet valve

    Hi Jack - I see that there is a cold water inlet valve under the unit. Are you saying that there is a turbine inside that valve that should spin freely? I took off the unit cover and don't see something that looks like a valve inside the unit.

    Curious how if that valve's spinning is relayed to the unit's control function because there is no wire connecting from that valve to the unit - only water goes in. I notice that the manual also says "Ensure turbine spins freely" (I had missed that "no code" row in the "error codes" table before) - how do I check that?

    Pardon my ignorance questions here. You also mentioned flow control unit - where is it located? Thanks a lot for your help.
  • Jack
    Jack Member Posts: 1,047
    The purpose of

    the inlet filter screen is to keep water borne debris from stopping the turbine wheel from spinning. The turbine is a precise measuring device. It is contained in the Cold water inlet valve immediately above the filter assembly Essentially it has an electronic pick-up on it that reads rpm and the units logic converts that to flow and combustion requirements to arrive at the set point temp.
  • JZZH
    JZZH Member Posts: 11
    Re: The turbine "in" the cold water inlet valve

    Jack - thanks for the explanation. It makes sense but I still have two questions - how do I check if the turbine is turning freely in my situation? How do I know if it's a problem with a stuck turbine or a bad flow control unit?


  • Jack
    Jack Member Posts: 1,047

    The flow control valve. Just inside the filter location is a snap ring. Remove the snap ring and with needle nose you can VERY carefully pull the turbine assembly out. There are two sides forming the body and the impeller itself. Take pictures or at least carefully note the layout of the impeller and two body parts. It's amazing how I have tied myself in knots putting those back together. Re-install and try it. If it isn't that get on the tech line. Number is on side of the cabinet.
  • JZZH
    JZZH Member Posts: 11
    Re: The turbine "in" the cold water inlet valve

    Jack - somehow I did not get a notification after your post so this is a late response.

    I assume the inlet valve is inside the unit (not the shutoff valve beneath the unit) and it is not obvious which one it is. But for now I don't have to worry about that anymore - after some time it started working then it stopped again. I then re-cleaned the inlet filter again and replaced the whole-house water filter. After a day or two it started working again (during the time I always try to use hot water, hoping it will flush out the debris) and has not stopped working yet.

    So indeed it is most likely due to a stuck turbine and luckily I do not have to take it apart to fix it. The lesson is to be diligent in replacing the main filter and clean the unit's inlet filter!

    Thanks a lot for your help!
  • Coldinwyoming
    Coldinwyoming Member Posts: 1
    Code 10

    We have had our Rinnai R53 for 6 years, never had a problem. Yesterday it stopped heating the water on two occasions. Then, later, it worked again. Tonight it stopped working again. I finally went and checked the heater and it shut off while I was there and started flashing the number 10 while beeping. I have no idea about the names of any parts of the machine, unlike most people posting here, and am pretty helpless. Are there any easy fixes or simple things I can check, or should I jut call someone who knows what they are doing? Thanks for any help. Oh, and I cannot find an owners manual, so I have no help there either.
  • OutinAZ
    OutinAZ Member Posts: 4
    code 10

    Most manuals can be found online. It's not to complicated to do some routine maintenance and cleaning. If your unfit table with any of it though it's best to get a professional.
  • Jim Godbout
    Jim Godbout Member Posts: 49
    Flush unit

    Most common problem is people do not service units they require at least a good flush every other year for best performance

    Find good tech in your area and this can be done very reasonably
    Jim Godbout
  • Jack
    Jack Member Posts: 1,047
    The manual

    Is available at www.rinnai.us. Select water heaters/model/documents and there it is. 10 indicates a high entering air temp. Could just need a cleaning. I'd suggest you call a dealer who has been trained by Rinnai to pull a service call.
  • Bigc27
    Bigc27 Member Posts: 1
    r75lsi code 12

    I keep getting error code 12.  when I turn on the hot water, i can see the flames start but within a couple seconds the code comes on?  any suggestions please.  I have a Rinnai r75lsi. 

    thanks in advance
  • DebF1
    DebF1 Member Posts: 2
    Rinnai Brand New system shower goes cold

    Just had new Rinnai tankless gas boiler and domestic water heater installed 3 months ago. Shower sometimes works fine, BUT sometimes the shower comes on fine but within 2 mins the hot goes off and I am left with cold water. The hot does not come back. Domestic heat works fine. No error code...service guy is perplexed....Help..thanks
  • SWEI
    SWEI Member Posts: 7,356
    Please start a new thread with this title

    and you will get more eyeballs on it.

  • heatpro02920
    heatpro02920 Member Posts: 991
    Service/installer should check....

    first the unit, obviously, if there are no codes, I would stand by the unit and watch it while you run the shower, if the unit stops making hot water but continues to flow water, there is an internal issue, most of which would be shown in the form of an error code....

    Next and most probable, I would look into your shower valve, and or your plumbing, could be a bad washing machine check valve, mixing valve somewhere, ect ect ect.. If it is just the shower, I would tend to look there..

    How about trying to run the shower, and a faucet does the hot water start hot and flow cold at both....
  • DebF1
    DebF1 Member Posts: 2
    Rinnai shower water goes cold

    Three month old tank less Rinnai boiler domestic water heating system, still cannot get the unit to work properly. The heat works great, BUT the shower goes cold 2 mins into shower. The unit services two apts. 600sq ft each apt. Kitchen hot water works, shower does not. The shower hot water stops 2 mins in to the shower for each apt. No error code. Hot water does not come back on. I have to wait 12-15mins to get back into the shower and then it does it again. Service guy perplexed...any suggestions? Thanks
  • Zman
    Zman Member Posts: 7,553

    I would suggest posting this as a new thread rather than burying in an unrelated 4 year old one.

    You would also get better feedback if you post the model number of you appliance and a picture of the piping around it.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Zeitgeist
    Zeitgeist Member Posts: 1
    Code 11

    I've got a Rinnai tankless unit that is about 7 years old. It just started flashing code 11 when the hot water is turned on and resetting the temperature.  I've checked on the code which explains that it might be insufficient gas or the igniter failing.  Just curious if anyone knows if this is an expensive fix, is this typical issue after this many years?
  • heatpro02920
    heatpro02920 Member Posts: 991
    get a tech out there

    have him check out the gas pressure and ignition, I don't normally see many rinnai service calls, it shouldn't be too crazy of a repair... While hes there maybe have him flush the system if you have never done it...
  • Snowmelt
    Snowmelt Member Posts: 1,405
    Dirt or leak

    Isn't 12 also a sighn of a dirty burner tray, a leak in the heat exchange or flam sencer have to be cleaned?
  • heatpro02920
    heatpro02920 Member Posts: 991
    12 is the nightmare code

    it can be almost anything, BUT it is most likely cured by a service and no parts needed... 11 will probably need parts...

    I have seen 12 caused by everything from a customer putting a gas grill too close to the exhaust and it diverting the gasses back into the intake to a blocked gas meter....
  • Jack
    Jack Member Posts: 1,047
    11 & 12

    11 means it tried to fire and failed to do so. 12 means it achieved ignition but couldn't hold operation. 11-no gas, no spark, combustion blower not turning, etc. As noted 12 is where you need your fast ball. That can be air related, dirty blower wheel not supplying enough air, grass clippings in fan, vent pipe separation allowing comb gases into fresh air pipe, did someone move the garbage can in front of the unit so it is recircing flue gas, dirty flame rod, inadequate gas pressure or overdrawn system. Same thing I guess. Bad gas valve. General system being dirty which could lead to lazy flame. Dirty burners. Could be a board, but that is unlikely.

    After 7 years and then a problem, it is time to get a tech in there.
  • heatpro02920
    heatpro02920 Member Posts: 991
    I hate to see that 12 on there

    Its rare for thee units to go down... I have never seen a bad board in a Rinnai unit, I have heard of them being replaced, but I personally never came across one, and I have seen them soaking wet...

    Propane units can need a cleaning here and there {mostly if they are being used for heat or have close deltas for long periods of time}, but for the most part the units are stable and reliable... Time will tell, they are getting more and more units out there so more issues will arise I am sure, but so far so good...
  • Caseyb
    Caseyb Member Posts: 1
    Error code 10 - R75LSi

    I'm looking for some suggestions on what might be going on with my Rinnai R75LSi. 

    A few years after I bought it, the unit would occasionally shut off (usually mid shower).  Turning the water off and then back on usually took care of the problem.  Eventually I learned that I had enough vent length (caused by elbows mainly) to require me to flip one of the dip switches. So I did that and the problem went away for a while.

    Its back now.  Last weekend I took apart a bit of the venting and cleaned out some spider webs / nests that were in there.  There were a number of them, so I figured that was probably the issue.  I didn't see any more when I put it back together either.

    Well, the code is still happening.  Any suggestions on what might be causing it?  I really don't think it is a blocked vent.
  • Fred1
    Fred1 Member Posts: 2
    code 12 on a 75lsi

    posted last Aug. about a continual code 12. Think we finally got it! when the exchanger was replaced, the gasket was not. The tech didn't have one with him so he heat sealed it on the outside and it has worked perfectly ever since. Hopefully annual maintenance will keep it running.
  • Rockhoppert
    Rockhoppert Member Posts: 1
    Rinnai RC98HPi code 12

    I have a code 12 that was showing on my unit, so no hot water. Also no flame visible through the site glass. Ithoguht this meant an electrical fault in the unit. Been trying for 2 days periodically and now all of a sudden it works again. What is likely causing the issue?
  • r306
    r306 Member Posts: 1
    rinnai on demand heater working on an off

    Hi,I have a on demand r5 water heater .Anyways sometimes it works good ,but lots of times when using hot water it will get hot then turn cold again continuously until you shut water off and on a few times .Then you can get it to work again.It puts out no error code .Could some one please help with this?

  • Blewis
    Blewis Member Posts: 1
    Rinnai Condensation Tube Clogging

    My condensation tube off my Rinnai has become clogged with a white sludge. I have noticed what looks like a metal residue in the past and this has never been an issue.

    Does anyone know what this white matter could be and is it possible to have metal filings/particles in the consensation tube?

    Thanks for aly advice/help.
  • Supernewf71
    Supernewf71 Member Posts: 3
    Code error 12 when really cold outside

    I will get a flame failure code when temp. Outside is in the minus 20 or so. I fixed the problem with placing a heater under the tankless heater on the cold nights. The heater is located I my basement of the house not outside. Wonder if the frost sensor is gone or something?
  • Jack
    Jack Member Posts: 1,047
    What model?

    Condensing or non? How is it vented? If it is the standard vent kit (90 on top and termination pipe thru the wall) is that horiz pipe graded to the outside? If this is only happening very cold conditions it could easily be from the gas regulator. Lp or natural? Also, this is the perfect situation for an undersized gas line to show itself. Error 12 is where you need your fastball. It could be gas supply, air supply. Is there another appliance vented in the same area? How far away? Depending upon age, I would consider throwing a new flame rod(s) sparker at it...but not first.
  • Shrubs
    Shrubs Member Posts: 1
    Condensate line

    My Rennai was installed in 2006. The stack run to the roof is approx. 3'. The stack above the roof is 3'. Installer stated that this run didn't need a condensate run. Is this correct?
  • Jack
    Jack Member Posts: 1,047
    The factory says 5'+ is the distance to require a condensate drain. I am very much more conservative. "If" you end up with condensation it can tear the hx up. I kinda take a "belt and suspenders" view of these things. Call me a chicken, but I like the protection of the condensate drain. I think you should too.
  • fulfill11
    fulfill11 Member Posts: 1
    I have a Rinnai (gas) that has worked flawlessly for 8 years. Beginning early this year the system began failing to keep a really hot temperature, but it was hot enough. By the summer, most all the heating was gone. I've had two service people out, Rinnai installers, who both assured me the unit was working and that the temperature at the unit was within 2 degrees of spec. The copper pip running from the unit is hot, all the way to where it turns upstairs, a point I can no longer reach. However, NO faucets produce hot water. Lukewarm at best. Unit has been serviced (January 2014). We did have a pipe that froze in extremely cold weather conditions in February. That problem was resolved. Other than that, there have been no plumbing changes. The two service personnel who came out replaced every cartridge of single valve faucets in the home. Still no change! I need help! Haven't called Rinnai myself, but the last service person did.
  • icesailor
    icesailor Member Posts: 7,265
    Where did this 4 year old to one year old string come from?
  • j a_2
    j a_2 Member Posts: 1,801
    Code 12 pull off small plastic tube at gas valve
  • j a_2
    j a_2 Member Posts: 1,801
    Sorry,hit the send button to early, if you have water in the small plastic line chances are gas valve is damaged…Does vent pitch out or back to unit?
  • Docfletcher
    Docfletcher Member Posts: 487
    JACK, When I see guys like you, having a firm handle on what customer service is really about... Well, it gives me cause to appreciate people like you. I don't have any Rinnai stuff in my home, but if I ever want the brand I'll certainly remember what I seen here.
  • Jamie Hall
    Jamie Hall Member Posts: 22,972
    First time I had read this thread. For TPwater, just above -- read the rest of the thread. Then go and have someone check your gas piping. Seems obvious enough -- but these tankless heaters (and the brand doesn't matter) take a lot of gas to run, particularly on high fire, and if the gas pressure drops too low... all kinds of mischief follow.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • icesailor
    icesailor Member Posts: 7,265
    "" First time I had read this thread. For TPwater, just above -- read the rest of the thread. Then go and have someone check your gas piping. Seems obvious enough -- but these tankless heaters (and the brand doesn't matter) take a lot of gas to run, particularly on high fire, and if the gas pressure drops too low... all kinds of mischief follow. ""

    I always looked upon it like an oil burner with a plugged filter. The supply gets starved, the pressure goes down, and the output goes down. How can anyone work on gas without pressure gauges? You can't seriously. Now, you need negative pressure digital ones or you are trying to fly VFR in IMC/IFR conditions. In other words, BLIND!!!.
  • Jack
    Jack Member Posts: 1,047
    Fulfill, if the unit is producing the proper output temp at the outlet on the Rinnai, and holds that temp at its maximum flow rate (given ground water temp + temp rise) then the unit is in fact operating correctly and you have a house plumbing problem. You can read the actual gpm output at the touch pad. As noted, do check the gas pressures with all gas appliances running and see if or how much it drops. The gas supply system may have developed a problem. Are there any error codes? Your install manual will tell you how to retrieve them and flow and output temp. Assuming the Rinnai is doing its thing correctly, try turning off the cold supplies at each fixture to see if it affects the hot temp. If it is a building problem they can drive you crazy trying to track them down. Please report back!

    Doc, thank you it is kind of you to say so!

    Ice, I keep wishing someone would begin a new thread. Surprisingly, Dan's new system took me directly to the new threads so I didn't have to scroll through 4+ years of history. Way to go Dan!

    Also, Ice, as the rep (in another life), it was not uncommon to meet a guy on a job site and he would not have any diagnostic tools. He saw no need for them. He had my number. There were some interesting conversation there. I had one young plumber call me and tell me to go see his customer who was having a problem with a Rinnai he had just installed. I told him I'd meet him there. He said, "no you go do it." He wasn't interested in learning about them. He said, "I do pipe." After I went out and repaired the install with a good guy, I called the kid back and told him he is to young to think he can make a living "doing pipe", Especially so as he was clueless about proper lay-out. It was fun! We agreed that he would only install my competitors lines from then on. "I do pipe." Honestly, I'm still amazed!

    For new posters, please start your own thread!
  • Supernewf71
    Supernewf71 Member Posts: 3
    just got back to wording about the tankless heater not working on cold nights because winter is fast approaching. The vent and the exhaust is a factory unit just about a foot up the wall and 90 degree straight out about a foot outside. the unit is a propane unit and it is 7 years old going on 8th winter. there is a propane furnace downstream from the unit in the gas line and it fires perfectly all the time. the propane tanks are about 12' away from the heater and just on the outside of the house. Usaully when the heater fails is when its below-20 C or more. after the electric heater is placed underneath it, it never fails. Curious if it may be the frost sensing switch or anti frost heater assembly gone?
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