Will a riser get hot if no radiators are attached?

bipbap

One of the risers in our 3-story building used to have a radiator on each floor but all 3 radiators were removed and the pipes capped coming up out of the floor.

Should this riser still get hot? Or no because air can’t be pushed out?

I want to add a radiator back but am wondering if the riser isn’t getting hot because it was disconnected from the main somewhere or if it isn’t getting hot because it has no radiators on it. Any thoughts?

bburd

As a general rule, if there is no venting the riser will not get hot because steam cannot get in when it is full of air.

It should be a simple matter to check the riser connection back at the main. It is not likely they disconnected it there.

bipbap

Ok yes it definitely has no venting at all.

I thought it somehow might still get warmish but it’s totally cold even when heat is cranking

mattmia2

maybe a little of near the main will get hot as it compresses the air, but if the air can't get out the steam cant get in. you could loosen the cap then take it off during a heating cycle and put it back on when you get steam. maybe wear some heavy gloves.

Long Beach Ed

Just curious: What heats the room now?

bipbap

It was a separate kitchen and living room which was opened up to be one combined room and so the living room radiator is providing heat for the whole space on a separate riser and the kitchen radiator had been removed

Waher

Without venting the riser doesn’t get steam due to trapped air. You could remove the cap on the pipe and install a reducing coupling to provide a threaded connection for an air vent in order to heat that riser in the meantime. Using risers as “heat pipes” is a common practice in small apartments.