Options for replacing obsolete product, "The Heating Box" (KD-HBC100)

go_outside

I have a product I’d like to replace called “The Heating Box,” (KD-HBC100) originally manufactured by “KyungDong America, Inc.”, which eventually became a part of Navien. It is paired with an Navien NPE-240A (NG). This system provides domestic hot water and radiant hydronic heat in our home. I am a homeowner and did not choose to install this particular configuration, but it is what I have. Please forgive me for inadequate use of terminology, etc. I’m happy to answer any questions or clarify anything.

The Heating Box is obsolete, and many of its parts are hard to find if not discontinued, themselves. One part, in particular (a simple check valve) is on its last legs, and once it fails, I’ll need another option.

I have read the few forum posts that I can about this particular product, “The Heating Box,” and it sounds like it wasn’t particularly well-loved in the first place, and was sort of a stand-in for something that would allow for both DHW and radiant heating prior to widespread use of combi boilers.

What I’m interested in learning is: what are my options for eventual replacement?

My Navien NPE-240A is fairly new (~5 years old), and it seems to work just fine. It’s the Heating Box that’s a concern for me.

I don’t know if there’s some kind of technology that can swap out in place of the Heating Box? My hope is to not have to start completely over, and leverage the NPE-240A while I can. But, if it makes sense to do a full re-do, then, that’s something for me to think about and be realistic about.

Thank you all in advance for your help — you’ve done a lot to help keep me educated on topics over the years.

pedmec

can you post a pic of your "Heating Box"?

mattmia2

It sounds like it is some valve or ciruclators and a heat exchanger and flow switch which could be replaced with those individual components. Might need a zone controller too depending on what sort of logic the boiler has built in and if you already have a zone controller or not. Could replace it with and indirect instead depending on how you feel about the way it makes DHW now and if you have the space.

go_outside

pedmec said:

can you post a pic of your "Heating Box"?

Certainly, here is a photo of the inside of The Heating Box.



(The pink circle was superimposed by me to highlight the failing check valve, otherwise it has no significance.).

I'll also include the Training Manual for the Heating Box as an attachment. In it, you can find this description under "What is the 'Heating Box'?"

The Heating Box is an integrated heat transfer control station that accepts hot water from a heat source and then re-directs it as required to provide domestic hot water and/or heat to hydronic applications.

It works to direct hot water traffic in the most efficient and effective way to satisfy household demand.

The Heating Box simplifies the design and installation of any combination domestic hot water and hydronic heating system. It facilitates the application of single source heating appliances, like a tankless water heater, with hydronic and offers the benefits of design time savings, easy installation, space savings and energy saving.

The Heating Box is prefabricated with the highest quality components and guided by the computer precision control necessary to perfect domestic hot water and hydronic delivery.

The Heating Box can also be used with any type of hydronic heating application including radiant in-floor heat, radiant baseboard, hydronic air handler, snow melting system, spa/pool heating application and much more.

It completes your combination system!

DCContrarian

It looks like what you've got there is a heat exchanger with two circulators and some control electronics. I would look into whether a Taco X-Pump Block can perform the same function.

https://www.tacocomfort.com/product/x-pump-block/

go_outside

I'll also include a few photos of the full installation, including the zone controllers, etc., with captions/descriptions above each ... forgive the dust.

This is a view of the full set-up. In here, you can see the Heating Box on the right, the Navien NPE-240A on the left, the pipework for the radiant floor below, and a "Taco" thermostat controller at the top.


Ground-level view of the pipework.


A closer view of the Taco.


And a closer view of the zone controllers (I think that's what they're called, anyway!).

EdTheHeaterMan

This seems quite simple. Set up your Navien NPE-240A to heat your radiant heat normally, You will need to reconfigure the pipes to a Primary/Secondary design. In the NPE-240A manual, there is a diagram for that. Then add an indirect tank for DHW. That is what I would do.

Oops the Navien NPE-240A is a water heater, not a space heater. Forget what I just wrote. Perhaps you can still use it as a water heater and set up the Indirect Tank in reverse. Use the Navien NPE-240A with a pump to run water thru the indirect Coil until it is at the desired water temperature for radiant floor heating, then use the tank side to operate the radiant floor heat. Since many of those tanks will outlast the tankless water heater, you can decide then if you want a space heating boiler or just replace the tankless water heater.

You may need some controls that you can salvage from the "Heating Box" like circulator pumps and realys for priority DHW. But it can be done.

Another option is to purchase a small heating boiler

EdTheHeaterMan

That Taco X-pump block may be an idea that will work. It will replace the control and the heat exchanger but I do not believe it will have the DHW priority that is in the Heating Box control. That may require an added relay and perhaps a flow switch on the Naiven to accomplish that function. The circulator pumps can still be pirated from the Heating Box. Since this was discontinued by Naiven, it goes to show that using a water heater to do space heating is not the best idea.

I say that the indirect is the better way to go for future ease of operation and equipment replacement. When the Naiven 240 needs to be replaced, you can choose a space heating boiler and turn the Indirect into an (almost) unlimited DHW source according to the new (years from now) boiler manual instructions.

Either way, I can help you design a control system logic to get you where you need to be.

DCContrarian

The check valve looks like it is meant to be replaceable. In the short run you're best approach may be to try to source a replacement.

hot_rod

Got a pic of the side of those valves? It’s an unusual looking check.
The removable cover makes it serviceable, really not much inside of a check valve. It could be a spring type check, so take care if you disassemble it not to lose any parts.

mattmia2

hot_rod said:

Got a pic of the side of those valves? It’s an unusual looking check.
The removable cover makes it serviceable, really not much inside of a check valve. It could be a spring type check, so take care if you disassemble it not to lose any parts.

there is also enough space and tubing there to replace it with an easier to find valve if it is just a flow check.