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Splitting zone with shared lines

davidv851 Member Posts: 1
Hello. I'm planning on some changes to my heating system (hoping to save on heating costs this winter), and I want to see if what I'm planning will work (or, more to the point, what issues there may be in doing things this way). As of now, there are 2 zones on my ~3500 sq foot home, hot water / copper baseboard. During the winter / evenings, we really only need to heat the bedroom. I have a programmable thermostat downstairs to allow that, but there are 2 bedrooms upstairs on the one zone / loop, and a single feed / return feeding them. Would I be able to install zone valves upstairs, keeping the shared feed and return? I realize that reducing the zone size too far can lead to noise / erosion / etc, and that I may need to adjust the thermostat / hydrostat settings to avoid short cycling the boiler and maintain flue temperature, but is there any hard and fast reason not to do things this way? I don't mind work / fine tuning things, but if I can I'd really like to avoid running new lines from the basement to the second floor.


  • Jamie Hall
    Jamie Hall Member Posts: 17,092
    In answer to the hard and fast reason... not really. However. First, you may wind up with one very small zone (that one bedroom) and, unless you have a buffer tank, the boiler will short cycle. Second, unless you have a delta T pump on the zone you are splitting, you will be overpumping when just the one zone is open, leading to a low delta T and high return temperatures.

    Third, and perhaps most important... you are really talking here about a form of setback, and setbacks usually (there are exceptions) don't save much energy...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • NY_Rob
    NY_Rob Member Posts: 1,370
    Just close the damper on the baseboard in the bedroom you don't want to heat. It will still keep it somewhat warm and no plumbing modifications needed.
    Brewbeerdelta TIs_solar