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Series/split: convert one bedroom to monoflo with TRV

Justaguy Member Posts: 1
edited October 2021 in Plumbing
Hi. I recently moved to a new house and with the heating season started we are experiencing too much heat in one bedroom to the point that occupant cannot sleep there even with fully closed enclosures. I made a full baseboard plan (attached), all pipes are in the basement ceiling and coming up through the floor to each room right into the baseboard and then leaving to the basement the same way.

Bedroom #2 is the troubled room. My question is, if i can convert that one room to monoflo-like system (option #1, with TRV valve after the supply split and diverter tee at the return split).

But i also saw that there is another work-around exists (option #2, with adding 1 size smaller bypass around the baseboard), both options are described in another attached drawing (sorry for the messy sketch).

I'm reading conflicting information here and there, some sources say that this would add too much resistance, mess up the flow and that eventually the circulator pump may overheat and die.

The goal is not only make the room colder, but give some sort of basic control of how much heat the room can receive with outside temp changing throughout the season, without spending ridiculous $$$ (i.e. making this room a separate loop with it's own thermostat & pump).

Kindly please help!


  • Jamie Hall
    Jamie Hall Member Posts: 22,085
    Option 2 is much the better one. Simpler, and less chance of it not working properly. I'd run the bypass line in the basement, and I'd put a balancing valve on it. Then adjust the balancing valve so that you get enough heat, normally, in that bedroom -- and use the TRV to close it off when you don't need the heat.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EBEBRATT-Ed Member Posts: 14,476
    not an easy fix.

    if you put a trv on bedroom 2 and a bypass pipe with a valve on it when they choke down you will be restricting the flow in the whole loop which may not work

    the sure fix is to pipe a bypass in the basement with a 3 way zone valve in the new bypass wired to a thermostat in bedroom 2. The new zone valve will send water through the radiation or through the bypass. You need to size the valve right or the added restriction will slow down the whole loop.

    Don't know if they make a 3 way TRV for this.

    you might get lucky with your other options, it's all about pressure drop

    Or you can try the easy fix. Cover the fins on some of the radiation buy wrapping tin foil around it