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 https://heatinghelp.com/contact-us/.

Boiler returns “throttled down”?

Hello! I’m new here but been looking on this forum for a few weeks now. A lot of good information! I just purchased my first house and it is equipped with single zone OHW boiler with 36” radiators. I have noticed the previous owners has all of the returns from the radiators “throttled down” with the ball valves. I can’t figure out why they would be like this. Are they trying to keep the heat in the radiators longer? I didn’t notice any increase in the pressure of my boiler it’s in the 12-15 psi when running. Any input would be great! Thanks to all and Happy Holidays!

Comments

  • nicholas bonham-carternicholas bonham-carter Posts: 7,500Member
    They may have had a thermostat placement problem, and were trying to compensate for some uneven temperatures.
    If you have a modern digital thermostat, is it set up for hot water heating, and is it placed in the ideal location?—NBC
  • hot rod_7hot rod_7 Posts: 9,026Member
    I agree that it was probably an attempt to even out the heat output from various rads. Panel rads or cast iron? Really about 3 panel radiators per zone is a good suggestion due to temperature drop.

    Turning down a valve does not equate to more output. Higher flow rates = higher radiator temperature and higher output.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • Ecobeast88Ecobeast88 Posts: 2Member
    The thermostat is set up to run hot water heating. Location is ok. The rads are cast iron. The 2nd floor is always warmer than the lower floor. I’m guessing because hot air rises? Would it result in less heat even if it’s the return being closed? I can see if it was the supply side. Thanks guys!
  • GordyGordy Posts: 8,453Member
    edited December 6
    Throttling down would not increase system pressure, but would increase system pump head.

    You say all radiators are throttled down. Are they all throttled the same?

    You say all radiators are 36". That would mean all rooms, or areas heated would have identical heat loads. Not likely.

    My first thought is system balancing. All valves throttled the same would not indicate balancing, or the person tried to balance, and didn't understand balancing.

    So if your observations are correct then the previous owner was throttling the flow rate to decrease output of the radiators in the entire system. if all ball valves are in same position, and the friction losses for piping to each radiator were the same.
Sign In or Register to comment.

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!