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firetube modcons piped full flow with zoning

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Comments

  • NY_Rob
    NY_Rob Member Posts: 1,370
    FWIW- most of the time my HTP UFT-80W is running for spaceheating it's just putting along on a very low setting not firing at 40K BTU's (I have combustion limited to 50% for spaceheating since my DD heatloss is about 30K BTU's). When one of the three zones closes, it's not a dramatic event that causes the SWT to instantly skyrocket. We're talking about low-fire 8K BTU's into a HX with 4GPM water passing through it at that point. It's a rather undramatic event in the end.

    The only time I see some overshoot now is if the heat has been off for hours (due to solar warming, etc..) and it starts up on high fire with 65F water entering the HX for several min. But, with the new firmware the boiler allows 5 deg or so of overshoot and modulates down vs. shutdown with the old firmware.

    It is encouraging that HTP actually listens to end users (not just jobbers) and makes changes based on product feedback. Don't know if other manufacturers do the same?
  • Gordy
    Gordy Member Posts: 9,546
    A 1gpm flow rate is about two to three loops of radiant on a zone depending on flow rate requirements.

    When other types of emitters are used I think you will seldom ever see that minimum flow rate. Maybe zoned standing iron on a gravity system.