Losing my mind w/ Noritz tankless

Discussion in 'Tankless Water Heater Forum' started by Ricker, Apr 3, 2017.

  1. Muffichka

    Muffichka New Member

    Joined:
    Dec 15, 2018
    Location:
    Los Angeles
    I hate the noise, it’s very annoying to live with it, esp since we never had this issue before the Uber-expensive remodel :(
    And, I can’t even imagine to start breaking up the walls...again...makes me want to cry.
    The master bathroom is right over the garage & that’s where the tankless heater is located. Is there a way to somehow disable the existing recirculating line & install a new one which runs, say, from master bathroom straight down & across the garage ceiling to the heater?
     
  2. Muffichka

    Muffichka New Member

    Joined:
    Dec 15, 2018
    Location:
    Los Angeles
    Of course I want to consider all possibilities, & the expansion in the pipes theory may or may not be the case here:
    I think I mentioned in one of my prior posts that I can actually hear those knocking sounds coming from INSIDE THE NORITZ HEATER when I put my ear to it! Those sounds are very faint inside the heater, but are somehow vastly amplified when it travels in the pipes.
    Has anybody heard of this phenomena?
     
  3. phog

    phog Active Member

    Joined:
    Jul 29, 2017
    Location:
    Rochester NY
    Hi Muffichka, sounds conducts very well through water and it's likely that the noise is just traveling from its point of origin, through the pipes, to be heard other places including the tankless heater. Although it's impossible to say for 100% sure, usually a noise will not sound louder farther away from the source. Usually it will sound fainter.

    Regarding disabling / reinstalling the recirculation line, anything is possible, and it may not be extremely difficult, but how difficult that would be is highly dependent on your specific home layout etc. I would suggest finding a plumber that you trust and going over your options with him or her, using what you've learned so far as a guide.

    Also, please do all you can to verify our theory before you start making any changes. The noisy expanding pipe is only a best guess based on your description, it is not a definitive diagnosis. We have narrowed it down to something temperature related, but that does not mean for certain that it is pipe expansion. Perhaps there is a new component such as a tempering valve (for instance) that is being affected by the hot water in a strange way. This online forum can be helpful, but it's not a substitute for a good on-site plumber!

    Good luck and let us know what you find.
     
    Muffichka likes this.
  4. Muffichka

    Muffichka New Member

    Joined:
    Dec 15, 2018
    Location:
    Los Angeles
    Thank you phog for all your thoughts and advice! You sound like a very knowledgeable professional who thinks. With all the new code mandated components for the water conservation faucets, etc. may be there is something in them to restrict the flow which can build pressure inside the pipes? What is a “tempering” valve?
    And you are absolutely right, a local ethical EXPERT plumber (I live in Los Angeles) who is not trying to rip me off with unnecessary “ideas” would be a start. Regretfully, as of this writing I’ve been unsuccessful in finding one. Even though my original plumber is knowledgeable, he has been very reluctant to diagnose the issues or do any additional work to rectify them. For the last year it’s been an uphill battle :(
    If anybody on this forum can recommend an expert & honest plumber (I know there must be a few out there), I would be most grateful. Again, thank you for all your help
     
  5. phog

    phog Active Member

    Joined:
    Jul 29, 2017
    Location:
    Rochester NY
    First i just want to state for the record that I'm not a professional. Just someone who likes this kind of stuff. You will find a mixture of professionals and amateurs on this forum.

    A tempering valve is a device that mixes a little cold water in with the hot water before it goes out to the fixtures. Its purpose is to prevent scalding. I was just making the point that there are other possibilities besides pipe as the noise source, and that you need a professional to look at your system as a whole. I don't specifically think you need to go looking for a tempering valve or anything like that.

    Finally, try not to go too hard on your local plumbers. You have a problem that even a really excellent plumber will need some time to figure out, and it might involve trial and error & multiple visits.

    By the way, if your new recirculation line is PEX (flexible plastic tube) then this could be a likely culprit. PEX expands more than traditional copper does, and since it's flexible it can be snaked through tight spaces that copper would never fit through. This can lead to some half-ass installation techniques. I would look for spots where the PEX recirculation line (if this is what you have) was snaked around a tight corner or through a tight hole at an angle.

    If you had a general contractor handle your remodel, and they hired the plumber who installed the recirculation line, this is maybe something that you might bring up with the general contractor -- it was their responsibility to make sure the job was done satisfactorily. You will probably get a lot of push back though, especially if it's been a long time since the remodel was completed. They're not going to want to touch anything that could involve opening up finished walls etc.
     
  6. Muffichka

    Muffichka New Member

    Joined:
    Dec 15, 2018
    Location:
    Los Angeles
    My pipes are all copper, no pex. It’s been a year & the entire year I’ve been bringing this issue up w both my contractor & plumber. Nothing was done :( I had another supposedly good plumbing company look at this problem & they were at a loss - without breaking the walls to see whether the pipes were securely fastened, insulated, rimmed, etc. there is little they can do to solve it :(
    That’s why I’m trying to figure it out on my own. Will see what the Noritz guys tell me today. Again, thank you for all your advise :)
    Really appreciate it.
     
  7. phog

    phog Active Member

    Joined:
    Jul 29, 2017
    Location:
    Rochester NY
    Document everything you can, especially all your communications with the general contractor & original plumber. If you told them about this issue right off the bat, and they did nothing about it, and you end up having to take the walls apart, you would have a basis to go after them in court to recoup your costs. I am never a fan of this route as it usually never ends up working out well for anyone. It's always better to come to an understanding. But it sounds like you've done everything right and are being asked to live with subpar work.

    In the future, if you ever do more home projects, you can often agree to a payment schedule with the general contractor and have it written into the contract. For example 30% down payment, 50% payment upon some milestone (for example everything installed & passed code inspection), 20% payment upon final full completion. In this case then you have a little bit of leverage, you can threaten to withhold part or all of the last payment to get them to work with you. Once they have your full payment, it can become extremely difficult to get anything further done.
     
  8. Muffichka

    Muffichka New Member

    Joined:
    Dec 15, 2018
    Location:
    Los Angeles
    Yes, I’ve already tried all the amicable options. My GC abandoned the project after I paid everything upon completion. Unfortunately, these hidden issues only came to light once we started living in the house after the remodel. I brought them up as soon as we noticed them. By that time work was complete & we paid in full. I hate to deal with complaints & resort to litigation, etc. but looks like this is where I’m heading :(
     
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    While remotely possible, I do doubt that the expansion noises you hear if you put your ear to the tankless are being amplified and are the source of your problem...it is very likely the hot water running through the pipe, heating it up, causing it to expand where it is jammed through or against something tight outside of the tankless. Now, finding that point or points may be tough. You might invest in a cheap stethoscope and try to pinpoint where the sound is the loudest and dig in there. The tankless is the source of the heat, but it is that heat along the distribution system that is expanding that's creating the issue. The pipe must be installed with that expansion/contraction accommodated. the further from the heat source, the longer the pipe will be, and with a linear expansion, the more total movement there will be. If it's say 1/4" at the end of the run, it would only be 1/8" half way. Between tight spots, depending on how the pipe is run and anchored, it might bend versus jump through a tight clamp or hole. Once it reaches a certain point, though, it will move rather than deflect, and that's what you're hearing.

    While it might be something else, it is highly likely that it's the pipe expanding, and not some other component.
     
  10. jjkyle

    jjkyle New Member

    Joined:
    Jan 21, 2019
    Location:
    San Diego
    The issue that I think we are all struggling with is that we simply don't have enough information. For example, what are the temperatures and pressures before the tank, after the tank / before the pump, after the pump, and what is the actual system layout? What devices are in the system that cause pressure losses? These are some of the questions that a thorough investigation would call for. Is the instantaneous water heater heating the water too high? Is there a faulty sensor? Is there a setting that can be changed? Is the water getting over heated and with the addition of the inlet negative pressure of the recirc pump causing the the vapor pressure of the water to be so low such that air bubbles are forming and then collapsing in the pipe near the bedroom after heat has been lost in the piping? Adequate information in the hands of a knowledgable person would be able to solve the problem. Hiring a forensic plumbing engineer might be worthwhile. I'm sorry this change has been such a problem but do let us know what the solution was when you solve it.
    [​IMG] https://goo.gl/images/CgzvgT
     
Similar Threads: Losing mind
Forum Title Date
Tankless Water Heater Forum Losing hot water on tankless Oct 9, 2018
Tankless Water Heater Forum Takagi TK-2 Gas Valve Not Closing After Use ?!? Jun 27, 2017

Share This Page