Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Best Value in Combination Hydronic / Domestic Boiler and radiators

tpayne Member Posts: 2
Hi there,

We're doing a remodel in SF on a 1000 sq ft top floor unit in an 3 floor building. The domestic water is calcified so its got to go. we pulled the old wall mounted furnace and want to do hydronic. Currently debating different radiators like rundal ($$) and Veha (>$ :). we need to keep the costs way down on this project but don't want to do slantfin. there is one shower head but also a spa tub.

We had a local plumbing house give us a quote for runtal and a Prestige excellence trimax. too much. so back to square 1. We're wondering if a challenger boiler with a small storage tank would do the trick, or whether there is something less expensive with Takagi.

we like price on the Veha radiators. would love to know why NOT to spec them.

thanks in advance!



  • heatpro02920
    heatpro02920 Member Posts: 991
    edited April 2014
    How about

    radiators with a small ci boiler instead of a mod con and then a direct fired water tank, that should be affordable...
  • Snowmelt
    Snowmelt Member Posts: 1,288

    That's a water heater not a boiler, you really shouldn't use it. Why not the combi navien, that' has a boiler seal on it.

    Again takagi isn't a boiler
  • SWEI
    SWEI Member Posts: 7,356

    will be important here.  In that climate, 1,000 square feet won't have much of a heating load, unless it's one of those mid-century glass and steel things.  The Prestige Excellence is probably 5x as big as you need for heating, yet its hot water capacity is inadequate for a soaker tub.
  • tpayne
    tpayne Member Posts: 2


    Really appreciate the help but I'm a total amateur here. What's a "CI Boiler" and a "mod con"?

    At this point, I'm leaning towards a cheap water tank in the basement to replace the domestic and small boiler in the unit to fire the hydronic, partially because the domestic supply is already coming from basement, is hard to tap into due to exterior routing. a small hydronic boiler in the laundry room would be easier to a) vent b) connect to the hydronic through the crawlspace and c) has easy access to 3/4" gas and electricity.

    I'd love to know what brands you would recommend.

  • Snowmelt
    Snowmelt Member Posts: 1,288

    That's a typical cast iron boiler

    We not suppose to talk price here.

    A weil mc- clain gold or a peerless boiler

    For water heater just install a rheem 40 gallon or an ao smith
  • heatpro02920
    heatpro02920 Member Posts: 991
    CI and mod con

    ci is cast iron {standard boiler you would see in most homes} mod con is modulating condensing {like a wall hung boiler}.

    I am going to guess you are under 40K BTU total heat load... so I would install a Weil mclain gold cgi25 and just a basic 40 gallon gas water heater, any brand, I have bad luck with them all, lol...

    That tiny boiler will last a long time and wont use much more energy than any of the high tech units available...
  • ScrewLoose
    ScrewLoose Member Posts: 20
    Cheap and fast

    For a small place in a such a climate as San Fransisco, and for on a 3rd floor unit, I'd go with a small Laars mini-therm if your code allows it.

    For the rads, I've found Myson SX series to be the most "economical" from various brick-mortar and online suppliers.

    Pipe it all on a home-run manifold with PEX.

    Probably can't get any simpler or cheaper than that.

    For the domestic water, get a Paloma Legacy tankless, no electronics and a standing pilot, more $$$ than a standing tank, but they're "cheap" compared to their high-tech siblings.