Arco steam Rad

MarkZeh

Heating Help friends.

have an old Arco CI Rad that originally operated off steam. Looking to re-task for hot water usage. Have the Arco 1959 guide downloaded from this site. To me it appears that the Rad will work 'as is' with HW as well as steam but for the removal/plugging of the steam air bleed valve and the addition of a water/air vent valve in the new location. Is there any reason why the Rad will not work for HW?

many thanks just in case I'm missing something

thanks again

bburd

We could tell in an instant from a photo. Rads that are connected across the top as well as the bottom of the sections will work on steam or hot water.

Jamie Hall

See my comment on your other thread. Since the hot water pressure is about twenty times the steam pressure, the odds of it leaking are pretty good...

MarkZeh

Jamie, rad is connected both top and bottom. Will snap and post a pic.
thanks

MarkZeh

So with that said, remove bottom plug from section opposite where the steam valve was connected? have seen some cast iron Rads where the water entered in from bottom port and exited from top port on same side or even opposite side. Just checking

thanks

bburd

Hot water is typically connected to both bottom tappings, though you could bring the supply in from the top instead if you want easier access to the shutoff valve. That is the best position for a thermostatic radiator valve (TRV) if you use one. Return should be from the bottom.

Unfortunately Jamie is correct in that you have a high chance of it leaking if you connect an old steam rad to hot water, which operates at much higher pressure.

MarkZeh

Bburd, thank you. Bottom entry and exit it is. That'll work. The Arco Rad is not the rad with the crack. Keeping that ugly issue under a separate thread. National Art cracked rad.
Thanks again for your good words of wisdom.

mattmia2

if you keep the flow rate reasonable it doesn't matter a whole lot which tappings you use unless the radiator is very large both on the same end might not work so well. finding leaks when you increase the pressure is really the issue.

MarkZeh

To all, many thanks for all the great suggestions. Pics of this rad attached. Small, 4 sec/4 tube rad without any cracks. Planning on opening opposite bottom port for water exit. Should work like a charm in the small BR. A little TLC gonna be provided as well.

bburd

That looks too small to heat most bedrooms in most climates. Have you done a heat loss calculation, or at least compared it to the rad size and relative exposure of the other rooms in the house?

MarkZeh

Bburd, sorry, bathroom. roughly 5' 6'. Calcs put heat requirement around 1480 Btu with Rad output around 1380. I can live with that. If slightly insufficient, will hunt for a slightly larger unit
thanks