cast iron steam radiators not heating evenly?

Question

i have a house, 140 years old, with beautiful cast iron steam radiators. they do not heat up evenly. i know they are not supposed to need to be bled. i have replaced the valves on the side that are supposed to let the trapped air escape, about 5 years ago. i think they might need replacing again, where do i buy good quality replacements. thanks

Answer 1

I think I run into this once in an old school. The radiators were self bleeders. But, if there's problems then I would do something to alleviate the problem once and for all. I would change it now. Why don't you just put in butterfly flanges and then bleed the valves twice a year? you could leave the old ones in to keep with the value with the "old style" and keep the new ease of the bleeding.

Answer 2

They need bleeding of trapped air.
Release the air via the valve on the side using the rad key.