NCB-240 Problems

[HomeownersHomestretch]

After getting out of the military (Go Navy), my wife and I decided to build a home in New York. Everything went about as well as it could except that we dealt with a plumber we should never had on site to begin with. Anyway, here we are, almost a full year later in our new home and most of the loose ends are tied up EXCEPT FOR THE HEAT & HOT WATER! My contractor says one thing, multiple plumbers have said otherwise, the original "plumber" who installed the system may no longer be in the country so here I am, posting in the boiler forum. I have A navien ncb240 that supplies heat to radiant floor heat throughout the house. It also supplies heat to a techtanium hot water tank. The DHW supply is not in use, I don't know why. Over the winter the heat would constantly go out on error code e.012, flame loss. When it runs, it runs hot between 145 and 175. The gas valve has been replaced, same problem. We have a 110 gallon tub that we have had trouble supplying with enough hot water. A few weeks ago we were getting brown water out of the domestic hot at our faucets. Took 3 hours of flushing to go clear again. The basement radiant loops went rusty months ago. I have my theories with what may be causing the error code to come in but I'm here for your input! So take a look at the attached photos let me hear your opinions! Thanks in advance!
Tim

 

[Reach4]

Is this using a new well?

When you refer to brown water, is that rusty water? Is there any galvanized in your potable water system or heating system?

 

[Sponsor]

 

[BadgerBoilerMN]

Looks like old school meets modern hydronics.

We design, install and service Navien DHW and space heating systems here in Minneapolis.

You will need some professional help to sort this out. Design-as-you-wrench rarely works.

First a proper ACCA Manual J to see if the 80-odd thousand btuh available are enough to handle the heating load.

Second, the indirect, assuming "techtanium hot water tank" is an indirect-fired water heater, is not a factory option. There is no reference, in the 79 page installation manual, to an indirect water heater or any sort of DHW storage. This is logical, since Navien is exclusively known for their condensing "tank-less" water heaters and of late, the NCB combi.

Any Roman tub would require storage or, at least, two tankless units to properly fill in a timely manner with minimum water temperature. There is reference to "cascaded" boiler and water heaters in the installation manual.

Your man was creative but missed some fundamental hydronic design principles, and like many, was over is head with this combi-boiler. It sounds like a good idea, but takes some discretion and experience to design and apply properly.

You will have to send a picture of the tank and its rating plate if you have one.

 

[HomeownersHomestretch]

My water is not well water, it is supplied by American Water. There's a whole house water filter, the anodes seemed to be in decent shape. It seemed to be rust, just from the hot side of the domestic water. I will post a picture of the tank ASAP. Any opinion on the mixing valves that are installed? I can't figure out what they are doing there other then possibly making the system run hotter. Thanks again.
Respectfully,
Tim