2 pipe steam system cold radiator

simon_skove

Three story single family house with one cold radiator on the third floor and one nice and toasty warm radiator. Supply to radiator is on top. Feed pipe above finished floor is piping hot to the valve. After the valve, first to vanes of radiator are luke warm and rest of radiator is ice cold. This one radiator has a key vent, possibly attempt to fix by previous owner. Could the valve be bad and blocking the steam? I can "feel" like I am opening the valve.

Fred

If the pipe to the radiator is hot, the problem has to be a failed vent/trap preventing the steam from being able to push the air out of the radiator.

simon_skove

None of the radiators have a trap. Only two have a cheap key vent with no temp or opening setting. Suggestions?

Abracadabra

You sure it's steam and not hot water?

Fred

I'm not familiar with key vents on steam heat. Is this a hot water radiator that was converted for use with steam? Did the Radiator ever get hot? Can you take a picture of the Key Vent and post it? Have you tried to find a replacement for it? Clearly the air is not venting out of that radiator if, as you say, the pipe is hot up to the valve. If the radiator has never heated, it may be possible that radiator was a hot water radiator that is not designed for use with steam. Is the other one with a key vent the same type radiator and does it heat all the way across? I'm thinking if the vent is not replaceable, it may make sense to find a good used STEAM radiator to replace it with but let's see a picture and what others have to say about it.

simon_skove

These are two photos of the radi in question. FYI: same radi in the other room on the third floor gets toasty all the way across. https://us.v-cdn.net/5021738/uploads/editor/12/mtjkbpv83bw9.jpg
https://us.v-cdn.net/5021738/uploads/editor/t0/ti15pic9hzpo.jpg

Fred

That key vent can't work for steam. Maybe this Rad was designed to be usable for both hot water and steam. In the case of steam, the rad has to have the air evacuated with each cycle of the boiler. That would mean you'd have to open that key valve manually with each cycle. It would seem to me that air would be pushed out of the rad through that lower pipe along with condensate. Are you sure there isn't a trap somewhere on that system that may have failed, maybe even in the basement? The only other thing I can think of is that maybe your supply valve is not fully open or that the dusc inside that supply valve has come off of the valve handle and remains closed, even though you think it is open. Have you taken that union loose and looked inside the valve?

simon_skove

Have not looked inside the valve. Pretty certain this is the right rad. Others in the house look exactly the same and work great. It is indeed a two pipe system with these condensate lines going all the back to the boiler.

Fred

One other thought, Is this radiator the last one on the Main? Do you have good, working vents on that main? It is possible, if it is the last one fed off of that main and if the venting isn't adequate or functioning that the steam is pushing all the air as far as it can towards the end of that main but can't push it that far if it has nowhere to push it out. Although you said the suppy pipe up to the valve is hot, so probably this thought isn't an issue unless it takes an abnormally long time for the steam to work its way up that riser and by the time that pipe gets hot, the thermostat is satisfied and shiuts the burner off???

Jamie Hall

That key vent is useless for steam. Leave it closed; it's not hurting anything that way, but it isn't doing anything, either. So the question is: why isn't steam getting in? it could either be the valve is closed, or it could also be that something isn't letting the air and condensate out. Follow that outlet pipe and see where it goes. If, for instance, it goes to a wet return, there's your problem -- and you will need a proper air vent on the radiator (not in the key vent location, however -- lower down, for steam) or a proper vent on the outlet pipe. Just one possibility, of course.

simon_skove

Vent on the outlet pipe? A tapped 90 degree elbow at the bottom of the radiator? Woud that help? Heard mention of a vent being necessary on my main. Two photos attached show the end of the main on one of three legs. Should I work a vent in on the top of this end line? And what is the purpose is the loop/drip leg like piping?

Fred

I'm assuming the first picture is upside down and the second picture is sideways??? Hard to get any bearings from these pictures. The pipe with the loop looks like it goes to the floor and has what looks like a typical mud leg on it (allows you to take the end cap off to clean out any junk) but in this case it looks like it goes all the way down to the floor and may just be there to support the weight of the vertical pipe. I'm not sure what function that loop serves. Hard to put the piping into perspective. Your mains should be insulated so that steam does not condense before it gets to the radiators. The question you did not answer is if that radiator ever worked? If you have to put a vent on it, it should be tapped into the side where that round circle is with a dimple in it, about midway up the radiator. If that radiator worked before, then we need to figure out what changed that caused it to stop working. Mains do need to be vented to move the steam through them quickly. They should be vented somewhere after the last radiator feed on each main. This set up looks so different though, I think one of the pros needs to weigh in on it. I'm sure Jamie can provide a lot more insight. Did you check the supply valve?

Abracadabra

If that's 2 pipe steam, think you need to have a trap somewhere along the return line.

nicholas bonham-carter

Let's see a picture of the boiler, and it's piping.--NBC

simon_skove

Boiler photos

simon_skove

More boiler photos to come. Also I am in my first season with this house. Not sure if the radiator has worked. I assume it was an issue, as the key vent thing was on the end as shown. But to repeat , that stand pipe to the valve does get really really hot.

nicholas bonham-carter

How about pictures of the other rads in the house-do they have any vent or trap on them?
Is there a good low pressure gauge (0-3 psi) on the boiler?
When a pressuretrol is bottomed out like yours, it can cause the linkage to become disconnected, allowing the pressure to shoot up.--NBC

simon_skove

Two pipes out the top of the top of the boiler.

simon_skove

Photo of furnace.

KC_Jones

Several things. I think a pro chiming in on the rad and associated piping would be good. Those first couple pictures of piping...false water line or some kind of trap for the returns? I honestly am not sure. Your boiler piping is in word....ugly. Copper is bad, main takeoff between boiler taps bad. Let's just say once you get the radiator working I would think about having that boiler re-piped properly by a steam pro. I don't think that piping is helping your system much at all and it's always possible it is causing some of your issues or other issues in the system. These systems should run silently. Do you get water hammer? Does it make much noise? Since this system is new to you, as a homeowner I suggest you buy some of the books from this site, especially We Got Steam Heat and The Lost Art of Steam Heating. They are a great read and will teach you a lot about your system and how to take care of it. I have a feeling you will get lots of comments after that last picture you posted.

Abracadabra

Another picture for me to add to my new upcoming book.. "How not to pipe a steam header"

Need a pic of the diff cut out. Pop open the cover on the pressuretrol and take a pic of the setting the dial is at.

nicholas bonham-carter

What they are referring to is the way the boiler has been piped against the instructions from the manufacturer, in pipe layout, size, and material. I do not know if this will void the warranty on the boiler.
If you download the instructions for the boiler, and compare that with what you have, then you will see a difference. As it is more water is being carried up into the piping, and that may be part or all of your problem, especially when combined with inadequate main venting.
The Lost Art of Steam will explain this in better detail-to bad the installer never read either it or the instruction manual!--NBC

Fred

Oh my. That copper header and those copper risers off of the boiler have to go. At some point those joints are going to give way under the stress of constant expansion/srinkage. Use threaded black iron to replace them. Make sure the riser from the boiler is the full diameter of the boiler tapping and that the header is at least one size larger than the riser diameter, all the way across the header to the equalizer(which should be black iron as well, at least down to below the water line.) I'm not sure this set up is causing the problem you currently have with that one radiator ( I still think air is trapped in that particular radiator which a vent on that radiator will solve but the copper is going to have you stuck without heat one cold, cold winter night.)

vaporvac

As another HO, I'm going out on a limb here: a two-pipe steam system without traps, operating with an extant Vstat is more than likely an orificed vapor system. I also have one, although mine is a Trane vaporvacuum system. If you show a wider shot of your boiler we may be able to determine what type of system you have as, the "odd" ones have slightly different requirements. In no event, should they have an air valve on the rad. This one was probably put in as a mis-guided attempt to fix poor main venting.
If you do have such an orificed system, it's possible you have a blocked orifice on the inlet side of that rad. I have a similar cold rad, but I believe mine is on a "t" with one below it which no longer has its orifice or proper valve, and thus hogs all the steam. This might be another explanation if you have a similar set-up.

Furnacelady

That is a very bad job, but it is old and had to work some what. Remove the return elbow at the bottom of the radiator in question, check for obstructions. Pour water down the return pipe in the floor if blocked, clear it. If not blocked, leave elbow off, crank up the boiler - you need 2 people to do this and 2 cell phones. One in basement by boiler switch to turn it off if steam starts to come out heavily, (8 to 12 minutes from start up) if hardly no steam disconnect valve on opposite side and repeat. Repair as necessary. Soon you will need a new boiler since no dielectric fittings were used due to two disimular metals, water and corrosion just like a battery corrodes. That is if it doesn't crack first. Worst case senario put a steam vent in place of the coin vent. If it is plugged in the return piping it will fill with water but it may be a slow drainer and not blocked all the way. Drastic conditions require unorthodox repairs. Roll with what you got. The hardest problem to fix is a man-made problem.

Steamhead

This is a Tudor system, which was also quite popular in Europe. The lack of radiator traps and the loop seal at the end of the steam main give it away. Go here for more:

https://heatinghelp.com/heating-museum/european-heating-systems-circa-1907/

Is there an air vent on the dry (overhead) return line?

gcp13

You need to find the air vents on those return pipes. That's the only way you can get steam in.
I grew up with two pipe steam, no traps with air vents on each bundy radiator And false waterline. It also had air vents on each dry return in the basement.
Works great as long as you keep that water seal

gcp13

The photos of the basement piping in the corner shows large steam feed and smaller return without any vent or plugged tee (where a vent used to be)
Then it drops down to the floor for a water seal. Each radiator needs an air vent not coin vents(made for hot water systems only)you could start with a vent rite

Steamhead

Uhhhh, this is a Vapor system. The radiators do NOT need air vents. The air goes into the return line and out thru one or more vents on the dry return in the basement.

gcp13

Could be but the photo shows dry return dropping down to water seal without any vents that only leaves one place to vent the rad. Unless you repipe below.
I would like to see photo of one radiator that works in this house or the rest of the piping.
I agree the boiler header needs to be repiped.

gcp13

Could the vents be placed upstream from that loop seal?

oldsteam85

I have a similar Tudor system and the advice Steamhead and Jamie Hall gave in the below thread was extremely helpful:
http://forum.heatinghelp.com/discussion/comment/1293340#Comment_1293340. If you search for "Tudor", there is a lot of info on the website.

Also had a 3rd floor radiator which was not getting hot, but once the pitch of a return was fixed, it worked well. The problem can also be caused by steam getting into the return of lower floor radiators, if they don't have orifices, and unbalancing the system.

Steamhead

The loop seal connects the far ends of the steam main and dry return. There should be a vent on the dry return near the boiler. That one vent would take care of the air from all the radiators. Can we get a pic of the dry return in the area of the boiler?

gcp13

Sounds right,still haven't seen any photos of venting or other rads.
Upper right side of boiler photo looks like a galvi tee that may have a vent on top