20 Most Recent Noritz 6.9 Gallon Residential Direct Vent Tankless Water Heater - N Questions & Answers

I recently started getting an error 90 on my N69-M unit. I finally got a hold of someone at Noritz tech support and they state this error is a general combustion/exhaust/air flow error. Here is what they suggested to look at.
Gas Pressure – The unit has a minimum flow rate for the incoming gas and if the system is gas starved, then you have some sort of obstruction or restriction. If this is a new install and you are getting an error 90, this is likely your problem but if this is an existing install that suddenly started getting this error, unless someone was monkeying around with any values you might have in-line, this probably isn’t your problem.
Air Flow – This is a ventilation issues caused by the build-up of dust, lint, etc that chokes the flow of cool air to the unit and causes the burner to overheat. If your unit runs for a while and then pops an error 90, this is probably your problem. They told me they get a lot of these errors when the unit is installed in close proximity to a clothes dryer, which makes sense. To resolve this, remove the front panel and blow out the intake holes and slots (I tried to shop-vac mine before blowing them out and I was amazed at how much the vacuum didn’t remove). After removing the cover, the first thing you should see is a system board that is covered by a black dust shield. The board is held to the unit by 3 screws (one on the top left and two at the bottom). Remove the screws and let the board dangle by the wires plugged in it. You should now be staring at the fan assembly. They suggested that I either remove the whole unit and clean it out or use compressed air to blow it out. I went with the compressed air route because getting the fan assembly out requires removing and eventually reinstalling 2 relatively small screws way in the back of the unit that you have no real easy way to get to. Blow/clean the fan out and then blow out everything else inside the unit. Reassemble and you are good to go, provided this is your problem.
Exhaust – You might see an error 90 if the exhaust can’t freely flow. Two things can cause an exhaust issue to throw this error. One is that the flapper valve on the outlet of the system sometimes gets stuck closed. This should be easy enough to fix. The other is an obstruction in your exhaust ducting or using too small of a diameter duct to exhaust the unit.
Hope this was somewhat helpful and prevents you from having to wait on hold forever for Noritz support or having to pay someone to fix your problem.

Probably a 12 or 21 code. Neither of which a Consumer can do ANYTHING about. Call Noritz 1-888-382-6568 and they will have a Regional Service/Repair Field Engineer call you and diagnose problem.
This is a sophisticated appliance unserviceable to Consumer but you may diagnose it with the help of the FE for Service Contractor to repair.
N069M-DV was discontinued 3 years ago replaced by N0751M-DV. Have you checked the inlet filter since you bought it? Is it on good soft water? It's a strong pretty dependable unit IF INSTALLED PROPERLY and MAINTAINED.

The trick with these hot water heaters is to keep the filter screen clean and flush the system with CLR periodically. Code 11 is ignition error. Is your gas valve turned on?

We at Fixya can't provide you this kind of information. Join a Gamer's forum. and NO I can't recommend you any particular gamer's forum.

you will need to explain more of where the leak is on the bottom. You have two plastic valves on the bottom and if the clips are not on exactly it will leak and if the person who replaced valves did not use vasoline when they put it back together the could have cut the gasket ring on the inside putting in back together and again it will leak. You have to determine where the leak is coming from to begin with using a flash light to get the exact location. .

backflush softener If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

I called Noritz error code 16 is a overheat problem. Noritz say's to flush your coil with vinegar or CLR.
Use a small pump to recirculate the CLR or vinegar through the system for 45 minutes and flush with fresh water. This worked for me.

push breaker fully off and then back on. gene h If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

it's just a cup screen,, when you take off the cap screw you pull it out claen i and put it back,, it is on the cold side only right before the unit connection

well it is time to get the the two way valves to both side, I would use only a product the noritz says to use.

Now if you cant get it you can get other products that break up lime and scale from you local store that sells plumbing product. I you can see I dont list a store or a product I am here to help you repair your heater, Not have you buy from one store or an other.

With that being said you can vinegar but dont use acid. If yuo "burn" the inside of the heat exhanger you jusy might be buying a new unit. also Please flush out the system with cold water for at least 10 mins. with the 3 way valves that should be very easy to do.

You also might have a lime build uo in the faucet also which will affect how they work. You may want to replaced and cleanout the cartridge and see if you have a lime build up. If that is the case you might want to think about a low priced water filter or softener.

Hope this helps you out and please dont for get to rate me, and Be safe

Tom

you need to recirculate cleaner through the unit for the lime build up.

Try turning on hot water before reseting power. You can go to Noritz.com and get a trouble shooting guide (manual) for your unit make sure you have the model #

It sounds like the plug may be loose disconnect it and look at the ends and make sure they are straight and no burn marks on them then plug it in firmly and see if that helps

You need to use a remote control to raise the temperature from 120 to 125. The part number is N-7649M.

The 16 error code occurs when the outlet temperature exceeds the set temperature of the unit. Typically this occurs when the unit has developed scale in the heat exchanger. I would initially recommend performing a descale on the unit to remove any scale deposits from the HEX.

see if a reset button. if not the heating elements may be bad.

There is a GFI on the bottom right hand corner of the heater. It is a black box with 5 wires on the bottom in this order: blue, white, green ground, black, and white. The voltage across the blue/white should be about 100VAC and the voltage across the black/white should also be 100VAC. If the black/white isn't registering any voltage, the gfi is tripped.

The GFI typically trips due to moisture in the unit; however, it can also be fried if there was a voltage surge while you were gone. Use a hair dryer to dry up any moisture inside the unit, specifically around the GFI. If the water is pooling or you see a visible drip coming from the top of the heater, you heat exchanger is probably leaking and needs to be replaced.

If you have voltage on both sides of your gfi, check the voltage at the remote terminals. You should have 15VDC. If there is no voltage, you circuit board is damaged and needs to be replaced. If there is voltage at the remote terminals but no display on your remote, then check your remote wiring.