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Lack of heat question

Someday you would be glad to have those, to keep your return water pressure from going over 80 PSI!

Count your blessings... :)


  • Tim McGee
    Tim McGee Member Posts: 3
    Lack of heat question

    My son is living in a house that has one zone of forced hot water heat. It heats four rooms. It's some type of two loop system, originally a steam system.

    There is one loop for feed. The pipe runs around the perimeter of the house and at each room, there's a tee that feeds the input to each cast iron baseboard rad. The other end of the CIR feeds into a tee that is part of the return loop. Between the input tee and CIR, there's a relief valve.

    It seems the first room in the loop is getting very warm and as you move down the feed loop, the rooms get colder.

    I'm figuring maybe an air block in the system. He's tried bleeding each rad at the relief valve but that ain't helping.

    Maybe not bleeding in the right order?
    Maybe blockage somewhere along the path?
    There's no valving to isolate each room. I was thinking of having him remove the pressure reliefs and put in a ball valve for isolation instead.

  • I've never heard

    of a pressure relief valve at each radiator. Do you have a picture?
  • Tim McGee
    Tim McGee Member Posts: 3
    picture of valve

    Here it is. It's labeled set at 12-15 psi
  • John Starcher_4
    John Starcher_4 Member Posts: 794
    That looks like...

    ...a pressure regulator, not a relief.

    I have no idea why those devices would be installed in the radiator feeds like that. I've never seen anything like it before!!

    I wonder if someone was attempting to do some kind of flow control with them? If so, it's a pretty bad idea. I would remove them.
  • Tim McGee
    Tim McGee Member Posts: 3
    Would previous setup

    being an old steam system have something to do with it?

    Any thoughts on why the lack of heat?
    Is my theory of air in system plausible?
    How to get it out?
    What about replacing valve with ball valve for isolation?
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314

    Starch is right that is a boiler feed pressure regulator. job must be near me if it is that goofy. I wonder if they have one feeding the boiler? Any pics of the boiler piping?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • John Starcher_4
    John Starcher_4 Member Posts: 794
    That's a good thought.

    You may be onto something there. I still think they are screwing up the water flow, though.

    You would probably need to isolate the radiation loop, drain it, and pressure test it at normal system pressure (12 lb?) to see how the radiators hold up. This, of course, would be done after removing all the individual regulators from the feed lines.

    Replacing with an isolation valve is an excellent idea, but will only prove to be practical if there are iso valves on the radiator returns, too.


    EDIT: I totally missed your air question, and yes, it's possibly a part of the problem. Bleeding should be done at the radiators, though, and not at the pressure regulator.
  • John Starcher_4
    John Starcher_4 Member Posts: 794
    Yeah, Brad....

    ...I didn't think about that - I forgot that return water only allows condensing operation when below 80 psi!

    Good catch!!!!
  • World Plumber
    World Plumber Member Posts: 389
    Remove them

    The pressure regulators are designed to maintain a steady pressure in the system. And designed to reduce the pressure they are generally set for 60 psi inlet pressure or higher and 12 psi out. If they have 12 psi coming into them what are they letting through. Pressure regulators are no a flow through device they need pressure to push the spring open to allow flow. The system should be at a steady state of pressure so the regulator is now acting as a blockage and preventing water from circulating through the radiators. A ball valve will allow the system to flow freely and operate. A globe valve will be easer to adjust if you decide to throttle a radiator back if the room gets too hot. But yes I would definatly take the regulators off the radiators and install ball valves.
    I hope this helps. But it physics if you have the same pressure on both sides of the spring the water is not going to flow and the radiator will not heat.
This discussion has been closed.