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Which Navien Boiler size for Radiant only system?

tacoenthusiast
tacoenthusiast Member Posts: 4
edited December 2024 in Radiant Heating

Hi! I need to replace my current 12 year old triangle tube Challenger (CC125). I use radiant heat through the floors as my only heat source and have a separate domestic hot water heater. I'm located in Baltimore, MD.

I have been quoted Navien NHB 110 and 150.

My house is 4470 sq feet of radiant heated space (through the floors) with closed cell spray foam insulation. It has 4 zones- I use 2 of them. I only use 2680 Sq feet of the radiant heat (2 floors— I leave the basement and attic off). I can't imagine ever using the basement (nice and toasty as is) but turning on the attic would be 3130 sq feet.

Are either of these overkill? I was reading about an early grave by short cycling and just want to make the right decision since I'm replacing it. Thanks for any help- I have no one else to ask ha!

Comments

  • SuperTech
    SuperTech Member Posts: 2,511

    I recommend staying away from Navien. I've seen too many of them fail prematurely, two of them didn't even last 90 days.

    kcoppPaul S_3IronmanGroundUp
  • kcopp
    kcopp Member Posts: 4,513

    What is up w/ the Challenger?

  • heathead
    heathead Member Posts: 236

    If your in Baltimore contact Frank he is a regular is on this site. He knows his stuff.

    All Steamed Up, Inc.

    310 Centre Avenue, Towson, MD 21286
    Contact: Frank "Steamhead" Wilsey, Gordon L. Schweizer, Maryland Master Plumber & Gasfitter # 20365
    Phone: (410) 321-8116
    Fax: (410) 321-6353

    Ironmantacoenthusiast
  • GroundUp
    GroundUp Member Posts: 2,274

    Oversizing is of lesser consequence with modulating equipment so either would probably be fine, but it'd be up to a heat loss calculation to determine. On a side note, I too would find a different contractor that doesn't install Navien- I have replaced 17 of them this year alone and the oldest was only 4 years old. One was only 2 months old and had a leaking heat exchanger already.

    SuperTech
  • tacoenthusiast
    tacoenthusiast Member Posts: 4

    All Steamed Up must have a backlog- I've called a couple times. Frank has been universally recommended across all forums. Tough timing here to need a replacement!

    Re: the challenger— it's 12 years old, never had maintenance on it until 2 years ago (purchased the home) and needs a new control board. It has been going in and out of heating since early October. Since Oct. I have replaced the igniter, gaskets and flame sensor and am still losing heat every couple of days. I wish I would have just called All Steamed Up in October!! thanks for all of your advice, it helps a lot. Got a new Bosch quote instead of Navien.

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