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2 Floor Steam to 1 Floor.

Hi, I have a 2 Family house with old one pipe steam system, how can I cut off heating to 2nd floor in a way that I can turn it in if need it. Second floor has split system that heats it up. Or better yet how can I reduce the flow of steam to 2nd floor in a way that some heating takes place but the rest 80% is done by the split system. 2nd floor is rented and I don’t live in that house so i’m looking for contingency plan and to be able not to pay myself for the heat in the whole house. 


  • franzsf
    franzsf Member Posts: 12
    One-pipe steam doesn't like being throttled. Radiator supply valves should be either fully on or fully off.

    Additionally, if you remove half of your radiation, your boiler will be significantly oversized for the remaining load, which will cause short-cycling.

    I have thought about doing something similar in the long term, with my upper floor having Mitsubishi ceiling cassettes that could heat that space.

    Figured when I need to replace my boiler, I might install two smaller boilers in parallel, so I could turn off the radiators on the upper floor during the shoulder season and run the lower floor off one boiler. But I know there are complications there too.
  • JohnNY
    JohnNY Member Posts: 3,052
    Install 1-pipe thermostatic radiator valves (TRVs) on all of the 2nd floor radiators. There is not likely to be a more cost effective way to do what you're trying to do.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Plumbing in NYC or in NJ.
    Take his class.
  • ethicalpaul
    ethicalpaul Member Posts: 4,174
    edited August 2022
    Put heavy folded blankets over the radiators, remove them or partially remove them to let more heat out. With blankets or TRVs, your boiler will become (more) oversized and will be more likely to short cycle, no big deal.

    Even less expensive, most radiator vents you can rotate them upside down and that will prevent steam from getting to those radiators.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,897
    edited August 2022
    As I see it, anything you do the reduce the heat (That you pay for) from going out to those radiators, like blankets or TRVs will easily be reversed by the tenant that wants to reduct their electric usage of the split system. (did I get your drift?)

    the only way to stop any heat from goin to the second floor is to stop using the heater. Whether disconnect the radiators or turn off the switch completely, and install a smaller first floor heater like another split system ...or something

    No easy solution here
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
  • ethicalpaul
    ethicalpaul Member Posts: 4,174
    I wasn't sure if that was his drift, but if it is, he can remove the vents and replace them with 1/8" npt plugs
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG