Hot water supply in top or bottom of cast iron radiators?

Timco

both pipes in bottom, bleeder valve on top. Heat rises. Top to bottom will work, but bottom in & out looks and works best.

T

PG

Best to pipe hot water supply in top or bottom of cast iron.....

radiators? I'm reusing some old, cast iron radiators, for a hot water heat job. They are connected on the top, so they will work for hot water. They were previously used for one pipe steam. So I have the option of removing either the upper or lower plug. I think the lower plug will give us a beter looking job. My question is, what will work the best for heating.....supply in top or supply in bottom? Why? Thanks

Anthony Menafro

Bottom feeds

As well as the look with the piping in and out of the bottom, you'll have less probability of becoming airbound this way.
Anthony

Mike T., Swampeast MO

If you're installing TRVs, you should MOST DEFINITELY put the supply from the top. Why? Better sensor placement and higher convenience.

If no TRVs, it really doesn't matter as long as you use opposite ends of the radiator.