Cast Iron Rads for Hot Water?

Robert_16

I'd like to use some used water tube radiators for hot water heat. They are set up for supply in top and returns on opposite end bottoms. Is this ok? Or should I change the supply to also feed in the bottom? Thank You

Adam_11

Supply into the top ,and return out the opposite side on the bottom.Hot water will remain at the top cooler water will exit the bottom.Half inch will more than satisfy the requirments of a residential radiator.Place a manifold on the wall and run 1/2 hepex to each rad.Ensure that you have an air vent on each rad. Hint if you are removing plugs one side has right hand threads the other will have left hand threads.Left hand thread bushing are very hard to find,so if you need one get a right and left hand nipple or get a left hand Rigid die and make your own. Good luck ,these are some of the head aches I have encountered in the last month installing refurbished radiators.Oh yeah ,make sure that you pressure test them for leaks before bringing them into the house.

Robert_16

top or bottom?

Why do I see a fair share that are fed from the bottom also? And they do look like they have always been hot water. Never run into the opposite thread problem.

Adam_11

You can feed them from the bottom or the top that is just how Burnham Heating Helper shows how to do it.Old Rads were put together using right and left hand nipples.Tighten one way and you draw the sections together.Consequently the section have right hand thread on one side and a left hand on the other side.Shafter Brothers in Montreal manufactures left hand thread bushings but they want 90 dollars each.What I did was cut left hand threads and then put a socket weld cap on leaving just the threads exposed.After doing that I tapped the cap for half inch.At least I dont have an unsightly nipple sticking out.