NORITZ Tankless Water Heater Problem
I had a NORITZ tankless water heater installed six months ago after doing an addition to my house. The original piping (copper) is 1/2" but the piping to the new master bath is 3/4".
Recently, the plumber installed the remote thermostat, and ever since the system shuts off periodically. Namely in the middle of showers in the new bathroom. But also, it seems (and always has seemed) that the water in the showers must be full-on for it to be hot enough.
I can't say what the base unit was originally set at, but the remote is set at 125 degrees, and when it goes out, we get a flashing 90 on the readout, then must restart the system. Very annoying in the middle of EVERY shower in the new bathroom.
I have heard that this may have something to do with gas pressure (and that the RENNAI systems don't have this problem?). My fear is that my plumber is just not experienced enough with these systems, and that the Noritz rep may be unwilling ot fess up to the fact that his system is not right for our gas pressure (if it is indeed the gas).
FYI: We have three bathrooms, and a front-load washing washer, and we live in Los Angeles. Any help much appreciated!
They ALL need to have very good gas pressure to operate, very possible they did not run large enough piping to it, if you have 2psi gas piped to a regulator right off the heater should be fine, but I believe if you have low pressure gas it usually needs to be 3/4" piping to the heater. Never seen the install manual of one, just what I have heard.
You can't fix stupid
Problems with gas-fired equipment should be
addressed to the original installer. If this fails, the manufacturer is the ultimate source of information. They are the best qualified and certainly obligated to help you.
I have the same problem with my noritz, mod.# N-069M-1, which I installed about 1 year ago. within the last month I too have had the same "code", although I have 1 1/4" gas main to the house and I have a 1" line to the unit.
Were you able to get the help you needed to resolve this issue? if so, Where? I sent an email and the response was that the person I need to deal with is on vacation till 07 Jan. '08 ! Thanks for any input regarding this.
Have the installer take out the remote and restore the default setting. If the problem goes away, it is in the remote or the temperature setting. Most men can take a shower at maximum 101 degree temps, women 103 maximum.
Try a 105 degree temp, if that works, you don't meet flow requirements at 128 setpoint. Sizing a tankless water heater requires selecting a unit that will operate at minimum flow and load. None of this is new, just new to US.
Fixed my "Flashing 90" problem for $5 in 10 minutes
I experienced the very same problem. My Noritz had run perfectly for a couple of years then all of a sudden it started cutting out and the display just showed a flashing 90.
I discovered (purely by accident) that when the cover was off the unit it did not fail. I fashioned 4 brackets to move the cover off 1/2" and since then it has never failed again.
I have no idea why this occurs. I live in Southern California and the unit is in my garage. It may be a temperature issue but why it would occur after 2 years of normal operation I do not know.
Anyway, its an easy test. Take the cover off and if it solves the problem for you, then install the brackets.
Of the two different plumbers, I've had look at mine, neither has suggested the gas. The installer blamed the cartridge in the shower fixture when after 9 months of perfect operation, my warm water (when showering) would shut off up to 5 times. The only way to get it back was to shut the fixture all the way off and start over. The cartridge did work for a while. But then, it started stopping again.
The next plumber said it needed flushed. So I paid a ludicrous amount of money to have them set it up so I could flush it myself and to have them do it the first time. After one more hot and cold shower, it worked fine for 6 months. Then it stopped again. I flushed it myself. Problem was at the end of the instructions for the isolation valves used to flush it, it said to clean the water filter--with absolutely no instructions on how to do that. I'd have enough that night.
A week later, I found instructions for cleaning the water filter in the owner's manual. It says, "if the water drain valve (with water filter) is covered with debris, the hot water may not run smoothly, or the unit may put out cold water." OMG. I probably could have just cleaned the #@!* filter to begin with and not paid for the isolation valves. EXCEPT--when I took the drain plug out (the picture for which shows the filter built right on to it)--there was NO filter. There was something inside the pipe, but I couldn't get it out.
So for another $150 on top of everything else, the plumber came and told me that the filter was in there and has to be removed with tweezers (doubt that) and was perfectly clean and the problem was the shower head (not the cartridge, the head). It works fine now (for maybe six more months).
My personal opinion is that the filter probably was dirty and he either lied or didn't really know what he was doing. Or, there was debris in the water line between the heater and the shower head that got flushed out when he took the shower head off.
Interestingly, I don't have a remote. According to Noritz's site, I should b/c it says that the remotes are only optional on other models. I have the 069. I think I got ripped off.
I gotta say, I regret having ever gotten a tankless. Liked the idea of conserving, but it has been a pain.
For what it's worth--also avoid Danze fixtures.
Last edited by kellym; 07-16-2009 at 12:32 AM.
Find your local Nortitz rep. The guy that trains the local plumbers and offers technical support. Explain problems, insist he come out. Also, find out from the rep, who the area plumbers are, that have taken training and install lots of units. Get names, not companies, and use them for corrections if required. The units work, when installed correctly.
If you have a 'lemmon' ,unlikely, the rep should back it up. If it is an install problem, the rep should spot it in minutes.
The main issue with tankless is that they require a minimum flow rate for the burner to remain on - usually between .5 & .75 GPM. If you are mixing hot & cold water during a shower & you have a low flow head it is very easy to cross that threshold & the heater shuts down giving you cold water. You then turn the shower temperature up & the heater kicks on. The dance begins. LOL. Tankless works much better if you set the temperature as low as possible. You won't get as many fluctuations. In some case I have had to remove the flow restricter in the head or faucet.
Gas pressure is rarely the problem alone. It is more of a gas cfm issue. Tankless heaters heat the water instantly as water flows through the heater. It require large amounts of gas for short periods. You cannot just remove storage heater & install tankless. 90% of the time the gas line is too small to deliver the 150 - 200K BTU that these heaters require. The gas line must be properly sized from the meter to the appliance. The tankless may work fine, but when another appliance comes on, it will not work. Also you cannot connect tankless to the existing heater vent. You can create extremely dangerous conditions if you do.
gas meter problem
Here in Oregon, one unit had to have the gas meter replaces as it was too small for the total house consumption!! The problem was similar to yours..
Ive had a Noritz tankless unit in my attic for the last 9 months. Model is N-069M-1. This tankless unit replaced 2 50Gal tank units. For the last 2 months, the unit will shut itself off AFTER a shower or something where heater is in use for an extended period of time (~15-20 mins). The error code i get is a flashing 16 (unit over heating). This has started happening during colder seasons for some reason. Frequency of the problem is every 3-4 days and basically the unit needs to be reset from the remote control (Stop/Start) to get it going again. I have the temp set to 120.
I have also had a 3 plumbers look at it. First plumber, who was the orig installer said that the unit needed descaling and the filter cleaned. HE descaled the unit with Vinegar (forwards and backwards) and tried to pull out the filter but was unable to. Then he mentioned to himself that he forgot these units dont come with filters in them. The unit ran fine for a day and the second day shut off again with flashing code 16. I called Noritz and they mentioned the filter needs to be in there or else this problem will occur.
To get another opinion, a second plumber came out (recommended by Noritz tech support) and looked at the problem. First he recommended that the unit is sized too small (I have a 4.5 bath house and the unit only supports up till 6.9gpm with the delta T of 30-35 degrees. Hence recommended upgrading the unit as this unit cannot handle the rise in temp even with one shower turned on. I live in North Texas by the way. He also mentioned that his company does not install Noritz systems anymore because the units have so many issues and the support from Noritz is worthless.
Anyways, problem still persisted and I called Noritz back to get help again. They again gave me a number for another plumber to come out. This gentleman came out, looked at the unit and reported some install issues. Nothing that would cause the unit to overheat and turn off. Then opened up the unit and cleaned the ignition nodes going into the chamber with an aluminum gauze pad. Charged me for his hour of work and left. He also mentioned that this unit is undersized for my house. Well, 2 days and about 400 dollars later, i still have the same issue.
My belief is not only did the installer and his supplier not size the application correctly, the unit is faulty as well. I am not really sure what the issue is anymore. Maybe I have a lemon. Any help here will be greatly appreciated.
I totally regret going with a tankless unit. Not because of the way the unit performs, but because of the lack of knowledge in US about this product and very little to no support from the manufacturers.
Last edited by DFW_Tankless; 02-02-2011 at 05:17 PM.
Reason: Spelling error
If you must have a tankless water heater...Eternal is smarter.