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Rinnai R53i-1

Paul SPaul S Member Posts: 1,219
hey everyone....i am having a problem with a rinnai tankless water

heater model#r53i-1....they have intermittent problems with the hot

water....for example it will lite then lockout 10 seconds later....then

there will be times that it will stay firing while the water is being

used for 20 straight minutes.....this rinnai water heater was installed

by a unknown company...there is no digital display to view fault codes

or adjust temp.....factory default for water temp is at 120f.....rinnai

heater is vented vertically about 14 ft to roof(the condensate drain on

the pvc vent has a plug in it , not drained)....i called the tech

support line and the technician couldnt really help me because the

digital display wasnt there....he asked me to checked the clear rubber

hose connected to gasvalve which is connected i think to the combustion

chamber and there was water in the tube????.....the technician told me

it was a faulty gas valve(coil sticking??) question ishow would

water get into that rubber hose ??? and does anyone think its a faulty

gas valve???

                           Paul S
ASM Mechanical Company
Located in Staten Island NY
Servicing all 5 boroughs of NYC.
[email protected]


  • Mad DogMad Dog Member Posts: 3,171
    hate to say it........

    By the time you figure outs what wrong and then get the parts, it will be cheaper to do a swap out.  How old is it and was it ever serviced? mad dog
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • JackJack Member Posts: 936
    If there is water in that tube

    You are looking at a new gas valve, absolutely. That tube is connected to the bottom area of the burner chamber. It has a nipple that sticks up probably 1/4-3/8" from the bottom so water cannot easily get into this tube. There has to be a LOT of water for this to happen.

    My suggestion, having done a lot of these, is that you lift the vent and inspect the head of the heat exchanger. Rinnai specs 5'vertical, max , without a condensate drain. You are at 14'. The condensate is flooding the vent trap and dripping onto the hx. On a call for hw it fires, boils off the water and leaves behind the crap you are going to see on the fins. That is a 3 row coil so if it is really crapped up, and you will know, it is also time for a hx. Additionally, your intermittent fire is due to the condensate dripping thru the hx and hitting the flame rod. That will interrupt the flame current and error 12, if you had the controller. Once the moisture clears the hx it then goes into the burners and further spreads its joy, which if you have water in the gas valve tube it has certainly done. If you end up repairing this unit, you will have to clean the affected burners. There are 16 identical burners in that tray. Once you clean the 3 or 4 affected burners take those low fire burners, which will be the affected burners and move them to the far left of the burner tray. Put the original three on the left in the low fire position. Having seen a lot of these improper installs over the years I can tell you that you will save time by disconnecting the unit from the wall and laying it on its back. This is a 5 min job...if they installed the isolation service valves and if the vent is properly supported.

    This is straight out a fault of the improper install. That is a good unit, when properly installed. $2 worth of clear vinyl tubing would have prevented this, as well as an installer who bothered to read the install manual. Mad Dog, as usual, has a point. You have to inspect this and looking at parts and labor determine the best course of events. Let me know if I can help further.
  • Paul SPaul S Member Posts: 1,219
    thank you

    Thank you mad dog and jack....andI already tried to have the customer replace this heater but they just want it repaired ...I already ordered the gas valve....I quoted customer to replace valve and drain the vent.....and also to install a rinnai relief valve....thre was no relief valve installed
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    [email protected]
  • JackJack Member Posts: 936
    Your reply doesn't

    mention the heat exchanger. Adding the drain and replacing the gas valve are the supplemental issues at this point. The real issue is the hx. If, and I am quite sure this is the case based upon what you describe, the fins are "healed up" with the evaporated condensate you are going to create hot spots that will create a leak in fairly short order.

    I think the instructions are supplied with the valve, but if not make sure you call tech service to walk you thru the process.

    Here is another thought. Pull the inducer motor and look up into the bottom of the burner tray. If water has gotten into that area, which is likely the air distribution holes in that area will be healed up. When you pull the burner tray clean those up as well.

    Who installed this? Was it a homeowner job?
This discussion has been closed.


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