Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

One radiator started being cold

dsan Member Posts: 4
​Hi guys, ​I have a 6 years old piping, refurbished cast iron radiators and a new boiler, everything worked well until a couple weeks ago, that one of the radiators in zone II started being cold, on and off, while the other three radiators in this zone were working as before. The valve is open and I have checked for air, also recently had a tech clean the boiler. Any ideas what could be the reason?


  • Jamie Hall
    Jamie Hall Member Posts: 23,270
    Hot water or steam? And if steam, one pipe or two? If hot water, how are the radiators piped?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • dsan
    dsan Member Posts: 4
    Hot water, and each radiator is feeding by manifold directly.
    JUGHNE Member Posts: 11,057
    Is this 2nd story? What is the system pressure?
  • dsan
    dsan Member Posts: 4
    First floor (top of basement). The system pressure in 19psi
  • Jon_blaney
    Jon_blaney Member Posts: 316
    Are the supply and return runs for these radiators hot at the manifold?
  • dsan
    dsan Member Posts: 4
    Yes they are hot at the manifold.