Navien NCB-240/110H Sizing/Efficiency Question

Users who are viewing this thread


New Member
Reaction score
Kalamazoo, MI
I was recently quoted a Navien NCB-240/110H to replace an old boiler for hydronic heating and my water heater. The quote was higher than I can afford to pay someone so I am planning on doing it myself. I have been reading everything I can and now I am wondering if this is the correct way to go for my house. For one, they didn't measure the heat fin length in each zone and based on other posts I am reading on this site it seems that this unit may be way oversized on the space heating side. However, we do use a lot of simultaneous hot taps at once frequently running laundry, dishwasher, and a shower at once. Plus some hand wasing thrown in. (three bathrooms in the house)
Anyway, I have three zones:

1 - bedrooms, totalling 60' of heat fins
2 - main living, totaling 66' of heat fins
3 - basement, totaling 16' of heat fins.

The basement zone just keeps things from freezing (lower Michigan location) and the thermo is set to 64 degrees. The ambient heat down there pretty much makes this zone inactive. In fact, I could do away with the basement zone and split it's registers between the bedroom and main zone if it helps with the overall efficiency.

Two main questions:
1 - Can this Model, that was quoted by a professional heating company to me, be tuned to run efficiently with the type of heating space described above? It seems like it is overkill. (But again it's probably for the main water demand)
2 - should I just replace the old boiler with a high efficiency boiler more rated to the actual BTU's that I need?
Any recommnedations?
2.A - If a combi unit doesn't make sense, I am still interested in tankless hot water for both efficiency and to eliminate the use of the old chimney. Any recomendations on a brand/model?

One last thought, should I add more fin length by adding more registers in the main area's? I have some walls with nothing on them so this is a possibility if it helps with overall efficiency without baking me out with heat.

Thanks in advance
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks