The Wall
Forum / Oil Heating / Reducing Coupling on Two Upstairs Radiators at end of run causing Problems?
  • Post a Reply to this Thread

    Reducing Coupling on Two Upstairs Radiators at end of run causing Problems? (19 Posts)

  • ww ww @ 8:51 PM
    Contact this user

    Reducing Coupling on Two Upstairs Radiators at end of run causing Problems?

    Two upstairs radiators on the far end of the run have reducing fittings from the normal size hot water pipe feeding the radiators of appoximately one inch plus or minus down to maybe a half inch copper pipe.

    It took awhile for the last radiators on top and bottom floors to get hot recently and wonder if that reduction impedes the flow of water and the circulation of the hot water to those radiators and others in house when there is a call for heat?

    Old Delco Boiler, Beckett AF, 2 family house, burner recently tuned up.
  • billtwocase billtwocase @ 9:00 PM
    Contact this user

    sounds like

    you have a mono-flow system. That would be normal size piping for that. Has there been any change to the piping? Burner down fired when serviced? Radiators been checked for air?
  • ww ww @ 9:32 PM
    Contact this user

    these are the only two radiators in house with these small pipes

      both floors get heated by the boiler and one circulator.
    no new piping. burner was serviced filters,nozzle,electrodes,etc.
    these small pipes were put in because the fittings couldn't be removed on radiators at the time and prevented the larger pipes from being used.
    This post was edited by an admin on January 6, 2014 9:37 PM.
  • icesailor icesailor @ 10:54 PM
    Contact this user

    Squared Off:

    "Pipes increase as do their squares".
    That means that it takes four 1/2" pipes to equal what a 1" pipe will do (or carry).
    They should have at least piped it in 3/4". It was easier and cheaper for someone (lazy) to run 1/2".
  • ww ww @ 6:22 PM
    Contact this user

    Photos of Piping

    Some photos of piping.
    This post was edited by an admin on January 7, 2014 6:23 PM.
  • billtwocase billtwocase @ 8:15 PM
    Contact this user

    looks like

    3/4" pipe to me. I would like to see basement pics of the piping. If this is set up monoflow, it will and should work fine. Looks like 1-1/4 piping?
  • ww ww @ 8:55 PM
    Contact this user

    pipe measurements

    these are all OD measurements:

    copper pipe: 5/8
    system inlet and outlet pipes from floor: 1 1/4
    reducer fitting in radiator:
    inside: 13/16
    outside: 1 11/16
    I imagine the reducing fitting in radiator can be changed. I was told this was done this way because this fitting could not be removed.
    From what I think and what I'm told this would cause a circulation problem.
  • JStar JStar @ 9:08 PM
    Contact this user


    1/2" pipe can carry about 15,000 BTUH. 3/4" can carry about 40,000 BTUH. Do you know the rating of the radiator?

    I would be more worried about the way it's piped. The supply should enter the radiator on top, with only the return on the bottom.
    - Joe Starosielec

    Guaranteed performance. Guaranteed energy savings.

    Serving all of NJ, NYC, Southern NY State, and eastern PA.
    Consultation anywhere.
    (Formerly "ecuacool")
  • ww ww @ 10:22 PM
    Contact this user

    supply and return pipes

    are on the bottom of all radiators in the house. No problems heating here except two on top. Only difference in all is the two radiators on top as explained with the small pipes.
  • icesailor icesailor @ 10:55 PM
    Contact this user

    Two radiators:

    I think that the radiator that was there in the beginni9ng was moved and the one there is the replacement. There is a notch on the bed molding to the left of the radiator and the other radiator feed goes past it. The bottom bushings have never been out of the radiators in place now. They set the radiator up on bricks but unscrewed the valve/unions and replaced them with those copper adapters.
    You really need someone that knows what they are looking at to decide how to proceed. The original radiator must have worked. If only the radiator could talk and tell its tales.
  • icesailor icesailor @ 10:31 PM
    Contact this user

    All crossed up:

    ""The supply should enter the radiator on top, with only the return on the bottom""

    Not necessarily. if it is a pumped radiator, it is better if both the supply and return are piped into the bottom. If the supply and return are piped to one end of the radiator, it may not heat the opposite end. If you put the supply on the high side of one end and the return is on the bottom of the other end, the heated part of the radiator can run on a diagonal with the outside of the triangle being cold. The longer the radiator, the easier it is to happen. The harder/higher it is pumped, the greater possibility it has to happen. It will do it the least when both are piped into the bottoms.
  • ww ww @ 11:08 PM
    Contact this user

    solution to situation...

    I think I'll at some point drain the water a bit from the boiler so that it will be below the top floor radiators. Then repipe this with bigger pipe and fittings. According to what I see here and what I'm thinking it will work better with the bigger pipes than what is in there now.

    one more thing..there are two radiators that are in the room and piped together.
    This post was edited by an admin on January 7, 2014 11:10 PM.
  • Steamhead Steamhead @ 11:34 PM
    Contact this user

    Not the first time I've seen this

    and it won't be the last.

    This was probably a gravity system, judging from the pipe size and spacing. Gravity systems used larger pipes because there were no circulator pumps back then, and this kept the resistance low enough that the water would circulate on its own.

    For some reason the original radiators had to be replaced- maybe they froze? The replacements came from a newer system that always had a circulator, and used smaller pipes as a result. But they did not replace the reducing bushings in the radiator to accommodate the pipe sizes your system uses. So the water is going everywhere but those two radiators, because the small pipes have so much more resistance than the originals.

    You have the right idea. But it might be well to have a pro do this work, since getting those old bushings out can be difficult if you don't have the right tools.
    "Reducing our country's energy consumption, one system at a time"

    Steam, Vapor & Hot-Water Heating Specialists

    Oil & Gas Burner Service

    Baltimore, MD (USA) and consulting anywhere.
  • SWEI SWEI @ 12:00 AM
    Contact this user

    Help me get uncrossed

    Most current radiator manufacturers recommend piping which will result in diagonal flow.

    Are they missing some critical data?
  • icesailor icesailor @ 9:19 AM
    Contact this user

    Flowing on a bias:

    I don't know what the radiator manufacturers are saying but, the new "modern" radiators are usually 1 1/4" or 1 1/2" on the bottom and 1" on the top. Either way, most I see, old or new are piped with the supply and return on the bottom. In retro-fitted old houses, they were often piped on the same end because of convenience. On gravity systems where the flow is slow but the volume is high, the hot water rose diagonally from the bottom inlet and rose to the top. Where the cooler water in the radiator, being heavier that the hot, went out the bottom return. Only in grossly over pumped system did I ever see a problem where the hot water went in so fast that it beat the cold water out. People that don't understand that the water flow through a gravity system without a pump might have the same flow as a properly designed system with a pump. Many look at all that water and thing that a bigger pump will do the job better. When in fact, it will make it worse. There's very little restriction in the 1 1/4" gravity pipes but a ton of it in the 1/2" pipes. I'll bet that the circulator is grossly oversized. If it was a three speed circulator, I bet the radiators would start working if they ran the pump on the lowest speed. Or, but a 4-way mixer on it and ran the system circulator on ODR. To prove my point, open the flow check so the system runs on gravity. Disconnect power to the circulator. Set the high limit to 140 degrees and let it run. In a few hours, both those radiators will be as toasty as the rest of them. Once the temperature evens out, the system will balance out. Like when you forget to close the flow valve when you work on a system or drain the house for the winter. The customer will be calling back telling you that the house is too hot and the thermostat is satisfied. It goes along with forgetting to turn the power switch back on before you leave. Both things I have done consistently.
  • SWEI SWEI @ 10:42 AM
    Contact this user

    Gravity flow

    is a different animal for sure.

    I was referring to European plate radiators, a la Myson or Runtal.  We derate them by 5% for inlet/outlet on the same end, but when there is room, we pipe them diagonally per the manuals.  I was just wondering if there was a better way.  Probably time to invest in an IR camera.
  • icesailor icesailor @ 10:50 AM
    Contact this user

    IR camera's

    IR Camera's are nice. Expensive too.

    You'd be surprised what you can tell with  IR thermometer gun. For a lot less money.
    A pumped Hydronic system is just a gravity system with a pump.
    Turn off the power to the circulator and open the flow check. Given time, the whole system gets hot. ODR will solve a lot of problems with Hydronic systems. Pumped or gravity because of the long run times with the same temperature fluid.
  • SWEI SWEI @ 10:53 AM
    Contact this user

    No arguments here

    When properly implemented, ODR and (more) constant circulation create a level of comfort that most customers have never experienced.

    I have a fantastic IR thermometer (Fluke 568) but I'm ready for the next step.  Been watching the prices drop for about a decade now.
    This post was edited by an admin on January 8, 2014 10:55 AM.
  • icesailor icesailor @ 5:50 PM
    Contact this user

    Wise move:

    Wise move to wait.
    I just bought a Ryobi Inspection Scope. A few years ago, an electrician friend bought one from HD and got it in sale for less than $150.00. I just bought one for $99.00 from HD. Fine for what I wanted it for. I'd have liked to bought a better one but for less than $100.00, I couldn't go wrong. I found an antique empty 16 OZ can of Miller High Life beer in the wall behind the shower in my FLA Condo.
Post a Reply to this Thread