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cant get the radiator in basement hot

dannyboy
dannyboy Member Posts: 7
I have a two pipe hot water system and am trying to get the radiator to heat up there are 3/4 inch supply and return that feeed a 7ft. section of baseboard on the second floor the radiator is lower than the supply lines and i used scoop tees and spaced them apart at the same width as the radiator which is 20" I put the scoop tees on the supply line. the tees are 3/4 x 1/2 tees,the 1/2 goes to the radiator which is piped with 3/4 so i came out of the scoop tee and used a 3/4 x1/2  90 to pick up the radiator the supply house does not carry full size scoop tees. Any suggestions??/

Comments

  • Basement Radiator

    So you have a 2-pipe system but you piped this radiator monoflow off the supply.



    Monoflow piping is notorious for problems with purging air.  You will not get any movement of water through that basement radiator unless you somehow purge all the air out of the piping and radiator.



    Do you have an air vent on the radiator itself?  If so, vent there until you get water coming out.  Did you install any kind of union at the radiator connections?  Vent these as well.  You may even need to go so far as to install purge valves or hose bibbs in the piping to remove the air.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Another Reason

    And if you have all the air out, it could be that even though you have spaced the tees as far apart as the radiator, the water, being buoyant, may not want to go through the branches of the tees because it's easier to continue on flowing through the main.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • dannyboy
    dannyboy Member Posts: 7
    basement radiator

    alan there is a coin vent on the radiator and i purged there also on this area of the system there is a purge pack which i also purged.the original piping arraingment had the 3/4 feed and return going to the second floor and before the pipes (in the basement) went upstairs there were two 3/4 tees one on the supply and one on the return( that picked up the radiator) all of the radiators and the one section of baseboard on the first and second floors are great apparently piping a radiator from an overhead supply and return is an art. before i installed the scoop tees i simply took the feed line directly into the radiator and came out of the radiator up to the second floor through the baseboard and back into the return then after purging what seems to be a simple hot water loop and starting the heat no flow the pipe going to the radiator was very hot and thats where it stopped
  • EricAune
    EricAune Member Posts: 432
    edited January 2011
    Tee orientation?

    The first mono-flow tee is directing the flow to the radiator, the second should be "backwards" creating restriction ahead of it so flow is directed through the radiator and then down the line to the rest of the system.  Is this the way you have the tees installed?
    "If you don't like change, your going to like irrelevance even less"
  • dannyboy
    dannyboy Member Posts: 7
    tees

    yes that is how they are installed, this is really getting interesting.
  • Is the main

    above or below the basement radiator?  If above, are you sure you have bled all the air out of any pipes dropping down from the main.  If not, you may have to remove the 90 degree bend pointing down, replacing it with a tee to install a manual or auto air vent.  But maybe the "purge pack " took care of this?  I don't know - it's hard to see what you have there.



    You could also try installing a ball valve between the two monoflow tee and see if the radiator heats up with the ball valve closed or throttled down.  This valve could also help with air removal, if any.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • dannyboy
    dannyboy Member Posts: 7
    edited January 2011
    ball valve

    I will have to try the ball valve between the scoop tees also thinking about changing the piping at the radiator itself as both inlet and outlet are on the bottom of the radiator perhaps plugging the bottom on the return side and taking it out of the top of the radiator will make a difference however all of the other radiators on the first and second floors are piped in and out of the bottom taps and are working fine. The supply and return piping for the radiator is above the radiator. The main is above the radiator
  • VictoriaEnergy
    VictoriaEnergy Member Posts: 126
    monoflow tees or a ball valve, but not both

    Are you 100% sure on your tee orientation?



    For the lower floor rad; the tees should have the first venturi on the return side and the seccond tee on the venturi on the supply side.  Picture the system water flow from left to right in front of you.  The left hand (supply) diverter tee will have the venturi on its right side, the seccond (return) tee should have its venturi on the left



    Everyone has got it **** backwards at lest once.



    Yup, I'll try to keep my dignity in tact, and say I've only ever got it wrong once...



    Monoflow tees were introduced as a way eliminating the ball valve in the main line.  By eliminating the valve, it made it acceptable to enclose the piping behind wall/cieling finishes.  If go with the ball valve, you'll be able to dial in exactly how much flow you want through the rad, but you'll need to keep it service accsesable.  Having both monoflows and a valve IMHO, is just adding exsessive head to your circ pump.



    Please post, and let us know how it turns out.
    Home Owners Please Note:





    You are receiving advice from some very skilled pros completely free of charge. One of the reasons I participate is to sharpen my own troubleshooting skills. So; did we get it right? I would be grateful if you extend this courtesy back by posting the final outcome of the issue you are inquiring about. Thanks
  • icesailor
    icesailor Member Posts: 7,265
    Basement Monoflows

    Monoflows were developed before ball valves.  There is a possibility they were developed before you were born. Look on this site for a very good detailed article on Monoflows. Because I don't have one in my hot little hand, I can't say which way the venturi faces on a fitting, but I DO know that there is a groove cut into the tee in the run on one side if the branch. There are also two arrows with the words "flow" stamped into the run of the fitting beside the groove. In the past, these grooves were painted Red. The arrows denote the direction of flow that you must install the fitting. If you put the fitting on the supply, the supply arrow points in the direction that the fluid will be flowing in. If on the return, the arrow points in the direction of the flow. If you install two mono-flow fittings, the grooves ALWAYS face each other. If you only install one fitting, the groove must always face the other tee. If you follow these rules, you can never put one in backwards because the tee is always facing the correct flow.

    As I understand it, you should never install a valve between the monoflow tees to force flow to an emitter because you will slow down the flow to the next set of fittings.

    If you have above the main emitters on a monoflow loop with below the main emitters, the water would rather go up than down.

    It is suggested to use two properly installed monoflow tees on an emitter that iare below the main. No matter what, the groove faces the other fitting. ALWAYS. 
  • dannyboy
    dannyboy Member Posts: 7
    tee orientation

    vic, i installed the tees with the direction of the flow (>supply < return from left to right) if i reverse the tees isnt that adding to my problems??
  • heatmiser
    heatmiser Member Posts: 16
    take out the monoflow tees

    i use regular tees with a ball valve in the middle.works every time. why waste your money on those expensive monoflow tees anyway. 
  • icesailor
    icesailor Member Posts: 7,265
    Removing Monoflow tees:

    That's what you do when you don't know how to install one pipe flow tees.

    Your plan works really well on radiators. To get the correct pressure on the down fed radiators, you have to force all that cold waiter out of the down fed radiator and it makes all the downstream radiators see cold water.

    Complications arise when you try to feed radiators above and below the main in the same circuit. That's what i thought zoning was for. To correct unbalanced loads.
  • dannyboy
    dannyboy Member Posts: 7
    tees

    the tees i have are scoop tees i think i will try venturi tees to get this radiator going, ive never had a situation like this before, so its a challenge
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