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Clogged return line

jc2lite1
jc2lite1 Member Posts: 5
I have a clogged return line on a 2 pipe steam system from a radiator that is over a crawlspace with not very much room. It has 3 90 deg. elbows before a union that I can access. I tried using a plumbers tape to clean but could not get past the elbow. Is there a cleaner I could use or should I just replace the section of pipe?
Weil McLain EG-50-PI 175000 2 pipe Steam Boiler System. 33+ years old.

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,832
    Can you make a hard pipe connection to the pipe and connect a garden hose to the pipe? Water pressure may be able to push the blockage out..... or maybe an air hose hard piped to the pipe that is blocked. you will need to open the other end of the blocked pipe to release the blockage and the pressure.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • jc2lite1
    jc2lite1 Member Posts: 5
    @EdTheHeaterMan I did hook up an air hose, vacuum and garden hose and all I could get with the garden hose was a trickle. I believe the piping was not pitched correctly for too long. When I exposed the first elbow just under the floor, it was almost like a cement paste that I scrapped out with a screwdriver. Is there a chemical I can pour down the pipe to free it up?
    Weil McLain EG-50-PI 175000 2 pipe Steam Boiler System. 33+ years old.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,832
    Nothing that I would be comfortable with. Time to replace the pipes, even if you need to rip up the floor or walls to access them.

    Can you abandon those pipes and run something new in an easier access place? What size pipe? Soft copper is available up to 1" (1-1/8" OD) for refrigerant lines that I have personally used. You can also anneal hard copper in order to bend it to fit where you can access both ends more easily. I don't recommend copper for steam piping but since this is a special situation, and copper does work for steam, I think the dead men will give you a hall pass just this one time.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    ethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    If this is a wet return -- and below the floor I'd be mightily surprised if it weren't -- copper is fine. When you reppe it, make sure that you have access to flush it out at both ends!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Big Ed_4
    Big Ed_4 Member Posts: 2,785
    I have seen a mineral blockage in a steam system get hard as cement...
    I have enough experience to know , that I dont know it all
  • jc2lite1
    jc2lite1 Member Posts: 5
    I figured replacing the pipes is the only option. Thank you for your advice!! Size is 1/2" black pipe. Which should have been 3/4 to start.
    Weil McLain EG-50-PI 175000 2 pipe Steam Boiler System. 33+ years old.