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how far up are radiator legs solid? (gotta make a height adjustment)

archibald tuttle
archibald tuttle Member Posts: 809
when i took this pic of an American Arco Radiator, I though it was obvious but about 2 and half inches up the leg the casting flares and i'm thinking that is indicative of where one might begin to suspect the internal cast passage begins. I need to cut about 7/8 inch off the legs after a floor replacement. i got called in after and the valve is right up against a wall and it goes literally into a brick center wall in the basement so i can't access either end of the 1 and a 1/4 valve nipple to heat it to possible put in a longer one or add an extension and there is zero play/lift on the pipe. the valve is actually working and i think cutting the legs of the rad seems the most expedient so just looking for any knowledge on internal geometry.


  • Ironman
    Ironman Member Posts: 6,372
    You better walk away from that one.

    What happens if you cut into the water jacket based upon a false assumption?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • neilc
    neilc Member Posts: 1,304
    drill the floor
  • archibald tuttle
    archibald tuttle Member Posts: 809
    hmmm, i'm not purely polly annish but i'm sure something could be cut off, the question is how much. now, i concur, maybe its remotely possible i could catch the internals that don't have a complete closed architecture at some distance up. i'm kind of thinking i could get away with 3/4 inch. that said, suppose not, well either you solder the thing closed or i'm going to see if i can look up a union spud that matches the valve because if i eff something up, i could dig up another rad to match. actually, that is another way to look at this. is there a brand of radiator that has shorter legs/lower tapping architecture cause there is nothing particularly special about the radiator so i could use a different one.
  • JimP
    JimP Member Posts: 22
    Floor around the legs for sure!
  • dopey27177
    dopey27177 Member Posts: 536
    Here is a no F up.

    In old houses the wood floor is generally 3/4" thick.
    Mark the legs with a magic marker, use a hole saw or speed bore to remove 3/4" of the finished floor. The sub floor is usually 3/4" to 1" thick and will support the weight of the radiator. That should help you with your project.

    Before you do this job measure again and again to see if your valve and union will match for the tie in.
    Best use a new valve and spud because your work effort is tedious.

  • archibald tuttle
    archibald tuttle Member Posts: 809
    I just hate to drill the new floor. yes, I have to keep telling myself, it will only be me who notices. If I could readily get the valve off I'd just add an extension and coasters but we're talking a lot of heat and angst about the quality of whats left. maybe i could cut some slices in the valve to break section out and then get it turning with a coal chisel and put the new fitting on with setting joint compound. Another possibility I could consider is cutting the pipe right under the valve and threading for an extension. I think there might be enough coming through the floor for the die to fit. i gotta check. I'm looking around for an effed up similar rad to test a cutoff on. i got 6 months to figure this out, so comments continue to be welcome for a while :-)
  • Gary Smith
    Gary Smith Member Posts: 363
    cut the valve off (cut through the valve and chisel off the remainder); add a coupler and close nipple to raise the location of the valve; add a new valve and radiator spud; raise the radiator on blocks to the height needed to fit the new pipe / valve location.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,170
    edited May 10
    I would try to remove the valve and the return elbow from the piping. a series of cuts and a series of heating with an acetylene torch over the next 6 months should yield the male thread you need for new radiator valves and return bend unions. After that, all you will need is a male by female pipe fitting top extend the 7/8" you need
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • Grallert
    Grallert Member Posts: 516
    I've cut them in the past but I've only cut 1/2" off. After that? Dunno. If you do get into the void you could possibly drill and tap the hole for a flush plug.
  • archibald tuttle
    archibald tuttle Member Posts: 809
    Grallert said:

    I've cut them in the past but I've only cut 1/2" off. After that? Dunno. If you do get into the void you could possibly drill and tap the hole for a flush plug.

    glad to see there are other folks out there who think like i do even if they aren't 7/8" risque.

  • archibald tuttle
    archibald tuttle Member Posts: 809
    @EdTheHeaterMan the extension or male/female fitting is just what i have in mind although at 1 and 1/4" diameter that fitting adds more than 7/8 inch but not ridiculously more. absolutely, been there before insofar as heating, cutting somehow getting the valve and the spud loose. but it sure does make me wonder if i could cut those legs cause the valve will probably last the life of the house in that service if i don't screw with it too much.

    it does also make me think if I could go to the scrap yard or online and find radiator with shorter leg pattern, i.e. height to begin with although that means i would need a matching spud so it still leads me back to wondering how much i could get aways with cutting.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,170
    edited May 10
    @archibald tuttle Either way you do it ... removing the spud from the radiator or removing the valve from the piping, you are in for the usual problems with removing something. As you already know the spud must match the union on the valve. Mixing and matching dissimilar union fittings never goes well.

    If you can find a replacement radiator for the one you are thinking of making the legs shorter, then you could try your idea. I would be afraid of trying it without a backup plan. Back n the day, the cost of a few more ounces of cast iron to pour into the casting was not a real consideration. So my guess is that the leg is solid pretty far up. But with the ability to reduce the amount of raw material over multiple units can add up and someone in the company that made your radiator may have had that idea. Less ornamentation on the casting leads me to think this is a lower-cost item and may have hollow legs. All those ounces of iron add up to a larger saving increasing the company profit in a place where no one (except you) will ever see it.

    Have fun, and let us all know what you come up with.

    Mr. Ed
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • Dave T_2
    Dave T_2 Member Posts: 63
    @EdTheHeaterMan nailed it. Understanding you might need to install a different radiator, cut off what you need to and you will know if a different radiator is needed. Finding a radiator with shorter legs than your picture shows whould not be too difficult. I would wager cutting 7/8" is not a problem at all.
  • Big Ed_4
    Big Ed_4 Member Posts: 1,722
    It would be a gamble cutting the legs on a sand cast radiator . You would need to raise the riser .
    I have enough experience to know , that I dont know it all
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