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Help dialing in cast iron baseboard overhaul.

Nackl87Nackl87 Member Posts: 12
Hi, I am hoping to get some guidence dialing in a hydronic baseboard heating system I have made some modifications to, in the process of rehabbing my house.
   Specifically, I think I need to resize my circulator pump, due to the modifications. 
    The home was built in 1970, and previously had a simple, but relatively new (2005) cast iron boiler, heating a bunch of copper fin tube convectors.
   I have done a bunch of research on this site, and others, over the last few years and decided to get a bunch of old cast iron baseboard radiators and overhaul them.
   I disassembled them all, had them sandblasted and powder coated, and reassembled them all, and currently have them plumbed in. I also added a bigger expansion tank to accommodate for the larger volume of water in the system. Everything is leak free, and the heat works well, except for that I get some water schwooshing noises, seeming to be from one radiator in particular.
   I don't know for the name of the type of loop the system is, but I'll try to explain it. 
    The output from the boiler (which is located 3/4 way towards north end of my simple ranch house) goes down into my crawl space, and runs 1" copper all the way to my south wall, where it than tee's off into 3/4" pipe. That 3/4" copper than runs along the east and west sides of my house, with all the radiators plumbed in series. The east and west runs than connect back at the boiler return, teeing back into 1" pipe back into the boiler. 
   I am currently running a taco 007 pump (because it's what was previously there) but I'm thinking it may not be the ideal pump for the way the system is currently setup.
 Can anyone offer advise on how to calculate the ideal pump for this setup? 
   Thanks 
   

Comments

  • mattmia2mattmia2 Member Posts: 1,863
    is it air? What kind of air elimination do you have and where is it located?
  • Nackl87Nackl87 Member Posts: 12
    edited September 20
    It could be air, but I have tried to bleed/purge as much as I can from the system, at least as well as I know how. 
      There is an air scoop plumbed in, above the boiler, in the return line above the pump,(which is located right on the boiler basically) it has a (new) bell and gosset automatic air vent mounted on top of the air scoop. I also have manual bleeder valves on each radiator. 
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 2,051
    You should draw us a simple drawing on the pipe and baseboard with measurements. We can help calculate if a 007 is the correct circulator for your system. 

    Is the offending radiator (baseboard) near the end of the loop?
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • fenkelfenkel Member Posts: 93
    Try to completely fill the system first...you might have some air still in it..  the tee from 1 inch pipe to 3/4 might be causing an issue with completely filling the system..
    Remember water is lazy..it will take the easiest path...



    mattmia2
  • Nackl87Nackl87 Member Posts: 12

  • Nackl87Nackl87 Member Posts: 12
    edited September 20
    Not the best diagram ever, I will have to add lengths of pipe runs tomorrow, but I hope it helps. 
      The offending radiator is actually the 10' on what is the top left of the diagram(southwest corner of house).
       I have tried to completely fill the system, and have run it up to temp and bled the radiators multiple times. In fact, I even added bleeders to both sides of the offending radiator, thinking that maybe I had a pitch issue that could be trapping a bubble in that corner, but It didn't seem to help. 
  • mattmia2mattmia2 Member Posts: 1,863
    edited September 20
    Your air elimination and pump location is the old way of doing it and isn't as effective as a modern configuration. purge valves that let you purge and valve that let you purge each half of the loop from the tee separately might help too. A valve in each half of the loop so you can stop flow in that loop while you purge the other.

    This is the modern configuration:
    https://heatinghelp.com/systems-help-center/pumping-away-piping/

    EDIT: Others can tell you if the pump is right. What specifically is the boiler?

    Since only that radiator is noisy it makes me think it is air in that radiator or the piping.
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 2,051
    Do all the radiators heat well? Just the 10' one sounds like a waterfall? 

    Did you by any chance notice if both the top and bottom ports on the radiator were clear befrome installing them? 

    I have two old pieces of CI BB which I sand blasted/painted after stream cleaning and pressure testing. I've reconditioned several CI radiators and BB, and the range of rust that can come out ranges from minor little bits to huge, potentially pipe clogging flakes/chunks. 
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Solid_Fuel_ManSolid_Fuel_Man Member Posts: 2,051
    With good pumping away, and a micro bubble air eliminator (Caleffi or Spirovent) any and all air problems will literally go away in a matter of a few days/weeks with heat cycling. I started "pumping away" 12 years ago and ALL of the systems now have 0 air issues. I cannot stress this enough. 
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
    SuperTechmattmia2Canucker
  • Nackl87Nackl87 Member Posts: 12
    I was not able to get pipe measurements today, but I will soon. 
       Correct, all the radiators heat well, including the noisy one, and yeah, a water fall is a fairly good description, though it tends to surge a bit too. 
        I had completely disassembled all the multiple sections of cast iron baseboard, and sandblasted, blew out the internals, and reassembled with new compression nipples on all. All the elbows connecting to the copper are new too. I feel like I cleaned them pretty well, but i agree it's also possible something could have been missed/flaked off. I am hoping to try to dial in any potential flow rate/air issues before I resort to pulling any of the radiators apart.
       What do you mean by "good pumping away"? Just running the system and letting the air elimination devices do their thing? 
       I see the micro bubble devices you referenced, where would I plumb something like that in? What is the benefit vs. the bell and gosset air vent on the air scoop? 
      Thanks 

  • hot_rodhot_rod Member Posts: 13,835
    What fill pressure are you running? Sometimes adding a few- 5 psi can help purge the remaining air. Higher pressure squeezes the air pockets smaller and they may flow back to the purger.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,307
    If everything else works it is an air problem. You have a series loop system wit two loops
  • mattmia2mattmia2 Member Posts: 1,863
    Nackl87 said:

    I was not able to get pipe measurements today, but I will soon. 
       Correct, all the radiators heat well, including the noisy one, and yeah, a water fall is a fairly good description, though it tends to surge a bit too. 
        I had completely disassembled all the multiple sections of cast iron baseboard, and sandblasted, blew out the internals, and reassembled with new compression nipples on all. All the elbows connecting to the copper are new too. I feel like I cleaned them pretty well, but i agree it's also possible something could have been missed/flaked off. I am hoping to try to dial in any potential flow rate/air issues before I resort to pulling any of the radiators apart.
       What do you mean by "good pumping away"? Just running the system and letting the air elimination devices do their thing? 
       I see the micro bubble devices you referenced, where would I plumb something like that in? What is the benefit vs. the bell and gosset air vent on the air scoop? 
      Thanks 

    Look at the pumping away link i posted above.
  • Nackl87Nackl87 Member Posts: 12
    OK, now I am putting it all together. Thanks. The terminology threw me off a little. I didn't realize pumping away was the configuration  you had mentioned. 
       I will perform the modifications, as I understand the benifits, but I would like to potentially  put it off until next summer if it isn't likely to do any harm to anything to use the system as is.
       Is it likely that after I cycle the system for awhile, and (maybe) occasionally bleed the radiators that the air will work its way out the way it is configured?
       Do you think it would be smart to still try to recalculate what the ideal pump would be, even if it has no ties to the noise issue?
        I feel like the cast iron baseboard probably has much more "resistance" (head?), than the copper fin tube did, but I am not a pro, so just spit balling.
       Regarding the water pressure, admittedly that was another question I had. I haven't touched the water feeder settings, since it was previously set. I am at about 15lbs with the boiler at idle, and 20lbs when the pump starts running. Is that ideal? How do I determine ideal? I added some pictures of the boiler, and near boiler hardware. I recently repiped the near boiler piping, mimicking what was previously there (multiple leaks). I also added an extension off of the air scoop where I could mount 2 larger expansion tanks. 
     

  • SuperTechSuperTech Member Posts: 1,391
    If you get rid of the old fashioned air scoop and replace it with a microbubble resorber and relocate your circulator so you are pumping away all your problems will be solved. 
    I would also replace the circulator with a variable speed ECM circulator like the Grundfos Alpha or the Taco VT2218.  That will make it easier to dial in the flow. Adding a Caleffi Dirtmag would also be a good idea. 
  • Jamie HallJamie Hall Member Posts: 13,404
    On the pressure -- assuming that you have a more or less normal sized house, you're fine.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
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