Bad Radiator

JAR

I have a cold radiator.  It is one-pipe steam system.  There is a single riser to the rear of the building and each of five floors has a radiator attatched.  Second floor stays cold across the fins.  All the other floors get heat from cold start within ten minutes and fully hot by 30 minutes.  

The second floor radator has a new C vent and it is pitched correctly, and the valve is turned completley open.   It will start to heat if we run steam for 45 minutes or more but this cooks the rest of the building.  Some of the other floors shut off their radiators.

What could be wrong????

David_53

I have a similar problem...

I don't have the solution, but I was thinking maybe there is sediment clogging the intake of the radiator? 

Enreynolds

Air locked

Sounds like your vent is not working correctly.  Try opening up another tapping (if there is one) on the radiator and see if it vents the air and heats up.  If it does, then you have some sort of blockage limiting the air from getting out.

Rod

Radiator Problems

Hi-  I'm assuming that you probably have already done this , but the first thing to do is swap the non operational radiator vent out with one you know is working. You also should check the radiator's slope and make sure it is very slightly sloped towards the inlet piping.

Here;s a link to an article of Dan's on radiator problems:  http://www.heatinghelp.com/article/96/Problems-that-plague-ONE-PIPE-steam-heating-systems/100/A-radiator-makes-a-gurgling-sound

While this specifically addresses "gurgling" problems the same things need to be checked in a ":No heat -slow heat" situation. If you can inspect the pipe providing stem for the radiator, make sure there are no sags that would trap water. 

Since steam pipes and radiators are be constantly "steam cleaned", they aren't likely to have sediment clogging them. Most sediment in the system finds it way to the lowest parts of the system - the boiler and the wet return.

- Rod

crash2009

A picture is worth a thousand words.

What kind of radiators do you have? 

Are they the free-standing cast iron type, or the built into the wall convector type? 

You said you installed a "type C" What brand? 

What brand and model of vent did you remove?

Does the boiler sight-glass show any signs of a leak up in the system?

Is this an apartment building, with tenants?

Do you have access to all the radiators in the building?   

Hap_Hazzard

Do you hear any noises?

If you hear any hammering or gurgling nearby there's a chance that some of the adjacent piping might be pitched incorrectly.

nicholas bonham-carter

swapping vents

just make sure that the boiler is switched off when you swap the vents from one radiator to another. one open vent hole can quickly fill a room with live steam, causing damage to painted and papered surfaces!

is there only one riser in this 5 story building? how close is the riser to the radiator? if the floor may have sagged, then the pitch of the lateral pipe feeding the radiator may be wrong, trapping water in such a way as to prevent the air from escaping through the vent, and thus, the steam from entering.

if you have some helpers with communication between the boiler room, and the 2nd floor, you may remove the vent, while the system is cold. then fire the boiler, while watching the radiator, as steam is rising. if the vent, was blocked, then steam will start to come out, at which time the helper can switch the boiler off. a new vent should fix this.

the vent on the top radiator could be a gorton d, to get the air out of the riser, as quickly as possible, but the other vents should be the same size. i assume there are adequate main vents in the basement. this may be a situation where the massive main venting needed should be at the top of the riser for evenness, and comfort.--nbc