NORITZ Tankless Heater--water temp fluctuation

Discussion in 'Tankless Water Heater Forum' started by shall, Feb 13, 2008.

  1. tilemom

    tilemom New Member

    Joined:
    Jul 13, 2007
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    personal trainer, nanny, very very part time tile
    Location:
    NC
    I hate my Noritz Tankless and have from almost the day it went in! It takes 4-6- mins just to get hot water. So for that time, cold water is going down the drain. What a waste. I have had mine in since 2005. UGH- almost every week I am thinking of going back to the "old fashioned" Tank of water that is heater ( aka water heater) but I don't cuz I am busy puting out other fires. We too have Temp variations. Ugh. I have to always warn my house guests that the water WiLL come eventually... just turn the shower on but brush your teeth, go to the toilet, etc BEFORE you go to get in the shower. Is this normal?
     
  2. tilemom

    tilemom New Member

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    Jul 13, 2007
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    personal trainer, nanny, very very part time tile
    Location:
    NC
    So the real question is....would it be best to just go back to a regular water heater?
     
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    Sep 2, 2004
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    Retired Systems engineer for defense industry.
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    New England
    When you had a tank, did it take awhile for the water to get hot at the shower? A tankless system, unless installed very close to the point of use would be only slightly different than a tank in the delivery of hot water. I think this system uses a small tank and can easily work with a recirculation system. that may solve you problem with either type of heater.
     
  4. Dana

    Dana In the trades

    Joined:
    Jan 14, 2009
    Location:
    01609
    No this is absolutely NOT normal. Either the unit or the installation is defective. A competent tech could diagnose it and possibly repair or re-commission it properly.

    After 6 years of use it's probably way too late to get any cash claw back from the original installer though.
     
  5. larryjay

    larryjay New Member

    Joined:
    Apr 26, 2011
    Location:
    los Angeles
    I'm looking at noritz site and planning to use this tankless water heater. now, I stumbled upon this post which made me hesitate. is there a relatively complete comparison between different brands? my local plumber recommended noritz to me.

    thanks

    larry
     
    Last edited by a moderator: Apr 26, 2011
  6. Dana

    Dana In the trades

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    Location:
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    The competence of the installer and the support of the distributor are everything. Some manufacturers have certification programs, others not so much (IIRC Noritz does), which means the installer at least made it through the training and passed the test, and SHOULD know how to install & debug it. Tankless installation is is much more akin to installing a modulating-condensing heating boiler than it is like installing a tank-type water heater. The burners are 5-8x the size of those found in 40 gallon tank HW heaters, and the burner controls much more sensitive to fuel pressure, the exhaust venting has different requirements/limits etc.

    So, if your local plumber has the certification (punch in your zip code, see if his name/company comes up) and has installed a dozen or more Noritz tankless units, odds are it'll be done right and you'll get at least a decade of reliable service out of it (maybe two.) If he never took the course, can't do math, and hasn't installed many low mass boilers or tankless HW heaters, maybe not. It's worth asking how many he's done. You probably DON'T want to be his first, unless he's more than just plumber with a minimalist gas-fitters license (such as, he's done dozens mod-con boiler installations or something.)
     
  7. Surfing Plumber

    Surfing Plumber New Member

    Joined:
    Sep 27, 2011
    Location:
    Orange County, CA
    it does take a little longer than normal to get hot water from a tankless. This is the same for ANY brand of tankless water heater. You are heating the water from hot to cold in a matter of seconds and you have to push flush out all the cold water in the line before you get hot water. But once you get the hot water, it is endless. People just need to be educated and adjust to their life style when switching to a tankless. Tankless is NOT magical, it will NOT give you INSTANT hot water. NOTHING will give you instant hot water unless you install a recirculation pump that is controlled with a timer + thermostat.

    It shouldn't take 4-6 minutes to get hot water. I am sure it didn't take 4-6 mins for hot water when you first install it. You prob need a service and flush out the scales that are building up in your water line.

    for step by step de-scale procedure visit here: http://www.noritz.com/u/descale_procedure.pdf
     
  8. Surfing Plumber

    Surfing Plumber New Member

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    Sep 27, 2011
    Location:
    Orange County, CA
    Larryjay,
    Noritz is the largest tankless manufacturer in the world. They only use the best components, such as the heat exchanger is k-type copper, which is the thickest and most reliable compared to other brands. I see you are in LA as well. Noritz's US headquarter is in Orange County, therefore you will have a lot of support locally. I have been installing Noritz for 5+ years now. I have installed many other brands before but Noritz has the least amount of call backs/complaints from my customers and best support from manufacturer. Your local plumber is right when he recommended you Noritz. Trust the professional
     
    Jon Shelby likes this.
  9. keldon11

    keldon11 New Member

    Joined:
    May 2, 2014
    Location:
    MI
    I just installed a noritz nrc98 ng condensing unit, I noticed that the temperature in my main shower would go up and down. After talking to customer service and troubleshooting it over the phone, they told me I have a cross connection. I narrowed it down to only my master bathroom shower having the fluctuation. I had an American standard mixet valve, single handle, multi directional. I had no problems with this shower with my tanked unit but who knows maybe when I did the install somthing got in the pipes or maybe the tankless is just more sensative. Anyway there were only two parts to my fixture to replace, I replaced them both. Still the same fluctuations. I decided that my moen fixture upstairs worked fine so I bought a new fixture and valve. The moen only turns left and right, doesn't pull out also. I replaced it today and my fluctuation is gone! I just replied to this because I researched it a lot and never read anything about this.
     
  10. Sevenfeet

    Sevenfeet New Member

    Joined:
    Apr 23, 2011
    Location:
    Nashville, TN
    I'm going to add to this conversation since it's been rekindled recently. I've had a Noritz N-069 model for 7.5 years. It gave us no trouble until about two winters ago when we started noticing what I would call "flameouts" during showers during the winter. In order to get hot water back, you had to turn water off, wait a few second and turn it back on again. It didn't happen often and by March, the problem ceased to happen. I was told by a plumber that the unit was installed with a gas line that was too small (1/2" vs. 3/4" which is in the installation manual). But we didn't get the problem corrected until this past winter when the problem resurfaced big time. And this time, turning the water off/on didn't seem to reset it.

    We got the service tech out and we installed the temperature control display which we'd had in a box but never installed the first time. The service guys replaced the gas line with a proper sized one and after a descaling, we thought the problem was solved. But within two days, the problem was back and we had a proper error code on the display (Blinking 90). It took 3 more service trips out to finally determine that the gas settings which had been tinkered with originally to compensate for the smaller gas line were now letting in too rich a mixture and we were getting flameouts because of that (stochiometry!). It looked like we finally had solved the problem...

    ...until this week. For some days, we've been noticing that the temperature of the hot water would sometimes fluctuate. And "hot" never seemed hot enough, especially for my wife's standards. Finally today hot water ceased again and I found the control unit with a "flashing 90" code. This happened three times this evening and the temperature continues to fluctuate between 90 and 106 degrees (the unit is set for 120). When this unit was operating normally, it would deliver 120 degrees every time all the time, and fast (I checked it with my Thermapen cooking thermometer...great product). Now it seems the unit is barely keeping up with the demand of one faucet...and tonight its crapping out like the cold water temp is under 50 degrees like in the winter (it's a measured 65 right now).

    A service tech will be back tomorrow. Honestly I'm not sure what to think anymore.
     
  11. keldon11

    keldon11 New Member

    Joined:
    May 2, 2014
    Location:
    MI
    OK my temperature fluctuations were only gone for a week or so

    So I am having the problems again, I surely would not buy a tankless heater again. I went tankless because I had two 40 gallon power vent tanks. It was cheaper to buy the tankless unit, initially that is. Now I installed it and I keep having problems. I now have a guy coming out next week to look at it for 180 bucks. I already replaced a shower fixture 140 bucks not to mention my time. I called Consumers energy to have them come out and upgrade my meter. Their engineer told me over the phone that I should run the shower and look at the flame on the heater to see if the flame is going out. If it isn't he said it was probably a bad unit. I wouldn't take that advice to heart, he was most likely supposed to come over and assess if I need a larger meter by the use of gas in my house. He must have better things to do. Anyway I will follow up on what the plumber finds.
     
  12. Penelope

    Penelope Miss Penelope

    Joined:
    Jun 22, 2014
    Occupation:
    Design / Build
    Location:
    California
    I also have a Noritz NR-981 Outdoor. Dedicated 1" propane line running to the unit. I also get temperature variations at both the shower and the kitchen sink. Kitchen sink is close to the unit, shower is on the other side of the house. The water will go totally cold for about 1 minute, then back to hot like nothing happened. Happens occasionally but not always. And this happens when NO OTHER FIXTURE IS OPERATED. I can't figure it out... Any advice on how to test the unit or what to look for?

    Shower is a Hansgrohe and the kitchen sink has a Herbeau faucet. Water pressure WAS off the charts when I moved in (100+) but installed a Watts pressure reducing valve and I've backed it down to 55, and then again to 40 psi with no change to problem. HELP!
     
  13. lifespeed

    lifespeed Member

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    Apr 27, 2007
    Location:
    California
    You are drawing cold water past the heater at a trickle, without using enough to fire the heater.
     
  14. Penelope

    Penelope Miss Penelope

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    Jun 22, 2014
    Occupation:
    Design / Build
    Location:
    California
    Interesting. Thanks Lifespeed! This does seem to happen when I turn the water for a few second while shaving my legs, or the faucet isn't on all that high.

    Does anyone know if a tankless water heater like this heats ALL the water that passes through it, or is it possible that the system "flushes" itself with some cold water, perhaps without heating it all the way or something, at the end of a heating cycle. I'm just guessing here... curious.

    Thanks! Penelope
     
  15. Penelope

    Penelope Miss Penelope

    Joined:
    Jun 22, 2014
    Occupation:
    Design / Build
    Location:
    California
    Interesting. Thanks Lifespeed! This does seem to happen when I turn the water for a few second while shaving my legs, or the faucet isn't on all that high.

    Does anyone know if a tankless water heater like this heats ALL the water that passes through it, or is it possible that the system "flushes" itself with some cold water, perhaps without heating it all the way or something, at the end of a heating cycle. I'm just guessing here... curious.

    Thanks! Penelope
     
  16. Jon Shelby

    Jon Shelby New Member

    Joined:
    Dec 26, 2014
    Location:
    Arizona
    What does a person do when there is no Noritz certified service person in the area? We are in Yuma AZ and purchased a house with a Noritz heater installed in 2006. Everything seemed fine until we got a code 16 and the hot water flow stopped. Our maintenance manual does not even address this code, so we had to search the internet to learn what to do. We reset to get our water back, and followed the descaling instructions the next day. Now the temperature fluctuates drastically and Noritz just tells us to call a service provider. Service providers here say they will just get on the phone with Noritz and charge us $80/hr. Called Noritz again and this time they said check the manifold pressure. However, we cannot find instructions anywhere on how to adjust if the pressure is wrong! Any insight on this? You seem knowledgeable about these units and we do hope to not have to rip it out and install a tank. So far we have verified the flow on both cold and hot water at 1.7 gpm, no fluctuation, and the temp fluctuates at any and all faucets between 95deg and 130 deg when the setting is at 115deg. The temp fluctuation cycles continuously about every 1-2 minutes.
     
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