One second floor radiator not fully getting hot.

Dan_32

I need help! I have a job with a 1 pipe parallel flow steam system. I have one second floor radiator that only the first three sections gets hot. I will give you a brief history of what I have done to date to try to remedy this. Some are remedies are unrelated to the radiator issue. I repiped the near boiler piping allowing for clean dry steam plus I had corrected a water feeder issue that was flooding the boiler. The system was water logged and full of gunk. The main piping had some cracked and leaking fittings do from severe water hammer which were repaired.
I have a Florentine two column radiator rated at 28 square feet up on the second floor which is my problem child. It is different from all of the other radiators in that is has connections and nipples on the bottom only. (All the other radiators have top and bottom nipples.) It is fed from at the bottom that has a 1" valve (Fully open) and a new air vent on the last section 2/3 up from the bottom. Good right? The 2" steam main has a 1-1/2" (pitched 1"/10 ft) horizontal run-out feeding a 1" feed to the first floor radiator which is getting hot. We corrected the tee so it makes the connection at a 45 deg angle and does not to drip condensate in the steam stream feeding the down line upstairs radiator. This 1- 1/2" line then reduces down to a 1" line via eccentric tee to feed the second 1" horizontal run out (Pitched 1/2" / 1 ft) to a 1" vertical riser feeding our second floor problem child radiator. I have flushed the main, the wet return, the horizontal and vertical risers with a lot of water. We removed the upstairs radiator and flushed it outside as well. I checked the 1" valve to make sure it was not restricted. We pitched the radiator back to the valve.
Side notes: The 1" riser going to the second floor must have been changed out at some time. It transitions from iron in the basement, to copper up to the second floor to the valve. Would this make a difference? It is not insulated and it is my intention to insulate it. Is this the cause? If I pull of the air vent I can hear water boiling or gurgling far away in the piping. The vent pants. I can feel air coming out then then pulling into the radiator. I corrected the pipe pitch so there can't be any sludge or pooling of water in the horizontal run out feeding this radiator. I added a main vent which helps tremendously expediting the steam to get to both radiators. I have included some pictures to help you visualize the job. PS. On the second photo, don't mind the two lower oil fill and vent pipes. Thanks in advance for you help.. Dan

KC_Jones

In the second picture I see a main, a main vent and 2 radiator run outs, what I don't see is the return pipe? You say it's parallel flow, but without the return what you are showing is counterflow.

Is the copper running inside an exterior wall? It could be condensing like crazy and just not allowing good steam flow. Just one thought.

Jamie Hall

That comment on air pulling in and out sounds a lot like a real condensing problem -- quite possibly in that uninsulated riser.

Dan_32

Thanks for your replies. You are correct. In that particular run out it is counter flow. There is no return. As for the riser location it is located inside the room, not with in the exterior wall. From your reply and others, it likes like we are producing a lot of condensate and it maybe due from the uninsulated copper riser. I will insulate the riser and see what result I get if any. Thanks for all of your help.

Abracadabra

What size are those copper runouts? They look too small.

Fred

I would also suspect the problem radiator is attached to the copper pipe that runs out the end of the main, right? With that size copper pipe, I don't know how condensate would be able to return with steam pushing right out the end of that main.

Hap_Hazzard

I have an oversized fin-tube convector under my bay window that used to barely heat. Then I started insulating my mains. Every time I got a few more feet insulated, the convector would heat a few more inches across. It still isn't heating all the way, but I could probably double-up on the insulation.