Cast Iron Radiators

Brad White_21

on the same responding zone will not be satisfactory. Each heats up and emits at different rates.

Your fin tube rooms will cool faster than your cast iron rooms is the short answer, especially if the thermostat is in the cast iron room.

If you reverse this and have the thermostat in a fin-tube room, the cast iron room will seem overheated.

The best way around it is to use TRV's on each and use constant circulation. Even then you will feel a difference.

Another work-around is to have the cast iron room on it's own zone (valve or circulator and boiler priority), but do you really want to do that for one radiator?

Ray Kruzick

CI Radiators

I would like to know how to pipe up a ci radiator in a copper fin system and will it heat up properly? Does it have to be feed from the bottom and drain out the top?

Brad White_21

Saw your other post, Ray

And I gave a similar answer as the others. At least we are consistent! But you are beyond that and I did not answer your question.

For cast iron (I love the small tube types myself) I like to pipe them top-in/bottom-out, but you can do bottom-in/top-out without a problem. Actually that vents the air better. When I did mine it was because I liked the way it looked and that the hottest water saw the warmest air leaving the radiator (counterflow). Academic really because most salvaged radiators are over-sized, IMO. You never get one exactly the size you need, and when given a choice you picked the bigger one, didn't you?

Brad White_21

Saw your other post, Ray

Oops. Hair trigger