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Broken Circulation Pump / Potential Heating Unit Replacement

torgotorgo Posts: 2Member
edited February 1 in Radiant Heating
Hey all,

I have a broken circulation pump. Currently I have a regular old water heater tank connected to radiant heating and domestic water. I had a tech come out, and they said my water heater was 12 years old so might as well just replace it.

They quoted me on a Navien NCB 240 for my 2 bedroom 1 bath home (1000 sqft) with 2 zone radiant floor heating. My neighbor (same townhome) had the work done exactly two years ago from the same company and same Navien unit. They were quoted and they paid $ for the work. Two years later, they are quoting $...

My questions are.
- Is Navien NCB 240 overkill for my living space?
- Is that quote reasonable? If so why the 40% price increase in only two years?
- Read some threads with Navien detractors here. Should I find someone who would install something else?
- Temperatures are about to dip below freezing ~25F for a few days. I have a 24000 BTU / hr fireplace I can run full blast to try to mitigate things some. Do I need to worry about my pipes?


  • IronmanIronman Posts: 5,084Member
    edited February 1
    First, discussing pricing is against site rules (see the yellow banner above).

    Second, a load calc and radiation survey should be done to determine what the actual heat loss of your house is and what the output capacity of your radiation is. I would seriously doubt that either one would be over 30k btus. So why would you want a 240k btu boiler? Over-sizing is a serious mistake in boilerland that will decrease efficiency and the boiler's life. Your tank water heater is most likely less than 40k btus.

    A combi boiler has to have a high btu input because it's heating domestic instantaneously. That's the holdback with that type of boiler, but people jump on them because of the lower price tag not knowing the inherent issues with them.

    Your radiant should never have been combined with your potable water. You have a large Legionella breeding machine!

    I would suggest a mod/con boiler + an indirect water heater as your best long term investment. Look at the HTP UFT boiler + a SuperStor indirect.

    If you want a combi, look at the Lochinvar Noble, but keep the sizing down to what is just enough to do your domestic requirements.

    Bigger is NOT better in heating.

    Bob Boan

    You can choose to do what you want, but you cannot choose the consequences.
  • JUGHNEJUGHNE Posts: 5,713Member
    For the time being, I would just replace the pump.
    The new pump would most likely be needed for a new system.
    This gives you time to considers options and not make a hasty pressured decision. IMO
  • GordyGordy Posts: 9,264Member
    Agree with above suggestions.

    Sounds like they are trying to get a foot hold in the town home market.

    I’d ask your neighbor how things are performing if they are like systems. Especially their fuel bill.
  • torgotorgo Posts: 2Member
    My apologies on talking about price. Just started freaking out. Wasn't mentally prepared for it.

    I will take your suggestions in to consideration.

    Thank you so much.
  • Hilex007Hilex007 Posts: 4Member
    I suggest 2 separate units: NHB + NPE-a.
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