Main Vents Selection / Steam Leak Issue

JuiceBox

Good Evening!



Since its about the time to start spending money on the heating season, I've begun to look into correcting some issues with the steam setup (one pipe) in our new-to-us-yet-old home. We went through the last winter fairly naively regarding why we had to consistently top off our steam boiler every few days. The previous owners of 25 years didn't think it was uncommon and once I started to do some research, I felt like I could most likely track down the issue(s) and correct it (them).



First and foremost, our main vents don't seem to close....so when the system is creating steam, it is easily seen venting from both of them. I'm not sure if the vents are bad or they are improperly sized... as this is all new to me. We have what I think are two main lines coming from the boiler and they both have the same type of vent (Dole #55) terminating the lines. I've included a picture of one end of the first main line and then another with the second one circled (took the picture outside our basement crawl, but have verified it is the same vent). The second picture may give you an idea of how the returns are setup throughout the house..they are generally lower and descending towards the boiler (the PVC below is to the drywell). The first main line is about 30 feet of 2.5" pipe and the second is about 40 feet of 2.5" pipe. Not sure if this impacts possible suggestions, but I know the original system had to have been added to when an extension was built onto the house in the 80s.



Last winter I replaced a couple of radiator vents myself which also seemed to be constantly open....and the new vents did the tricks. I'm sort of guessing I should do the same with the mains, but want to make sure I get the right ones for the job.



The other source of our boiler needing topping off is a condensate leak off a radiator connection in one of our upstairs bedrooms. This hasn't posed a real problem other than the annoyance of aiding in the steam leakage and the noise of the condensate evaporating off the hot return pipe on contact when the system is working.



Also, I'm assuming my first read should be "We Got Steam Heat", correct?



Thanks for any insight anyone may pass along!

Rod

Main Vents

Hi-  Yes , I would say the first step is to get "We Got Steam Heat ! as it is a very good introduction to residential steam heating and will explain all the basics, terminology etc. of how your system works to you. It's humorous easy reading and in a few evenings, will put you light years ahead in your knowledge of steam.



Main vents- I'm guessing your main vents are Dole #5 s   They aren't located in the most idea position as where they are, they are exposed to slugs of water travelling through the mains which will then hit and after time destroy the vent.  They are also rather small in capacity aqnd should be replaced with Gortons. When we know a bit more about you system we can then go over this more.

Leaks in a steam system should be considered an important problem and need to be immediately fixed. Constantly adding new (fresh) water to your boiler can shorten the life of the boiler as new water contains dissolved oxygen which can be very corrosive to your boiler. It is very important that when any fresh water is added, that the boiler immediately be brought to the boil as this drives off the excess dissolved oxygen. (Things like this are covered in "We Got Steam Heat!)

So we can understand your system better I've attached your pictures with some notes. In the one picture with the long main is the slope in the direction I have placed the arrows?  

In the second picture of the 2 mains which way is the slope?  Main "X" - "A" or "B" ?

Main"Y" - "A" or "B"?  Which direction is the boiler? "A" or "B" ?

I would help if you could post a picture of the radiator with the leak and also pictures of your boiler and the piping attached to it. Take the pictures from all sides and back away so we can trace where the piping goes. If we need detail we can blow up the pictures.

- Rod

Jamie Hall

Definetly...

you need to replace those main vents.  A vent is supposed to close tight when steam hits it; if it doesn't, it's busted, and it's amazing how much water that might represent.  Also, you need to fix that condensate leak -- which may be much easier said than done, depending on just where it is.



As Rod noted, adding fresh water to a boiler to cope with leaks can cause real problems with the boiler over time, and shouldn't really be necessary.  To give you some idea, the system I superintend used -- for all of last year -- about two gallons of water, exclusive of blowdowns for the low water cut off.

JuiceBox

Re: Main Vents Selection / Steam Leak Issue

Thank you for the responses!



Rod - I'll try to give some insight. Generally, I feel as though you are correct in your slope assumptions in your first image and then in the other one, the slopes are downwards towards A. I don't think that the pipe you have labeled as "Main Y" in the one image is really a main. Also, I double checked the vent circled in red in the one image...it looks like it says "Frevent" on the side of it and is about a third the size of the one in the other image. I would go out on a limb and guess this one is very undersized. You're response inspired me to go fairly in depth with the attachments, but it seems like this will help you look into my system!



Jamie - Thank you for the input! I knew the behavior of topping the boiler was not a correct one as soon as I did a tiny amount of research. I'm surprised the previous owner didn't realize something was up!



About the layout and pictures...I've tried to label it so that it is intuitive. This is a layout of my basement. I'm calling the mains the lines that terminate with vents "v". The thinner lines off the mains are each going to a radiator (or 2 radiators). I've accounted for all of my radiators and am fairly certain that this is correct based on the placement of the pipes going up the walls from below. Just an "r" indicates an older original radiator (some of them have been moved from their original locations) and "br" indicates a newer cast-iron baseboard radiator. If i put a "+" in between, then the line sources 2 radiators. The number next to the radiator notations indicates what floor the associated radiator is on. There is a single line that was removed and caped off of one of the mains - its indicated by a "c". The light blue line indicates a line that snakes all the way around my basement wall and seems to be a dedicated return for condensate back to the boiler. The stack out the top of the boiler also connects back to the return right near the boiler (seen in image 4). The grayed out areas I cannot get to as they are closed crawls. Finally, the orange numbers and symbols on the diagram indicate the picture number and the general perspective of where I was looking while taking the photo. Oh, and just a note...The bend going over the main in the middle of the layout doesn't have 90 degree turns...its just for pictorial representation to show which main it is actually connected to.



The final picture is of the radiator connection that has a condensate leak. Its leaking where the arrow is pointing. It is a pretty slow leak and water pools right on the lip of the pipe coupling. When enough water accumulates, it trickles down the side of the pipe and evaporates fairly quickly... I know there is no inner-wall damage from this, but I can bet that the pipe may be difficult to mate with considering the rust that is going on. Have no idea how long that has been going on.



Thank you for the help!

Rod

Steam Leak/Boiler Piping

Hi- Thanks for the great pictures and layout! They really help!  We now have a far better idea of your system’s configuration.



Radiator leak ( See attached picture) - If  I’m reading your picture correctly, the radiator valve is on backwards and someone has just “mickey moused” the valve onto the steam  pipe coming up through the floor.

Radiator valves are normally connected to the radiator with a spud which connects to the valve using a faced flange joint (like a pipe union)   Radiator Valves are supplied  with a spud and should be replaced as a complete unit as the spud pipe and the valves aren’t really interchangeable between brands.

 The following is a good video on replacing radiator spuds.This is for a different type valve on a Hot Water radiator but the replacing of the spud is the same operation. http://www.thisoldhouse.com/toh/video/0,,20258687,00.htm



Boiler Piping- From what I can see it looks like you  have a Weil McLain boiler. Is that correct? Could you give us the model number of the boiler?  Who ever did the installation obviously didn’t read the installation manual.  The configuration of the  steam piping connecting the boiler to the mains is incorrect. You don’t have a proper header.  What you have now has to be producing very wet steam which isn’t very efficient and uses more fuel.

Here’s a link on this which maybe of help: http://www.heatinghelp.com/article/321/Steam-Heating-Basics/128/A-Steam-Heating-Primer



Here’s is also a video of Dan’s on the importance of proper  boiler piping configuration. http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping



It doesn’t look like it would be too hard to reconfigure your piping. Could you take aphotos of the boiler from the front and from the sides as then we can see what is attached to what and what needs to be changed.

- Rod

Jamie Hall

Well, yes

that is a different way to install a radiator valve.  However.  The point where the leak seems to be occurring is not that uncommon a place for leaks; that is actually a type of union joint, and depends on the faces of the union being clean and smooth and drawn tightly together by the nut.



You may very well be able to loosen that nut, where the leak is, and then gently (very gently!) raise the radiator at that end enough to be able to look at the union joint faces.  They should be clean and smooth; if they aren't, you can try to clean them with a cloth or something of the sort -- but don't file them or use sandpaper or such like.  Then put the joint back together.  A little lube on the threads will help, and I have found that gently -- very gently, again -- rocking the radiator will often help getting the joint to pull up tight.  Union joints are not meant to correct misalignment of pipes, though -- if you find, for example, that when the joint comes apart that the two ends are not aligned, see if you can shift the radiator enough to get them lined up before you try to put it back together.



I do not recommend putting sealant on the faces of a union joint.  The only time I would do that is if the face of the joint is so badly damaged by corrosion or leakage (or a big scratch -- it happens) that it can't seal.  Then a very thin bead of sealant might be used.



I wouldn't try to remove the valve from the radiator, nor the other half of the union from the riser, except as a last resort.  Too much chance for things to get busted.

nicholas bonham-carter

topsy-turvy union

i may be misreading the picture, but i think the union threads, which seem now to be screwed onto the riser pipe, are proprietary only to the spud, and will never seal properly.

thus the only solution would be a new valve installed properly.--nbc

Rod

topsy-turvy union

Hi NBC- That's the way i read it too!  Someone tried to make the spud nut into a compression joint. A new valve and spud need to be installed the proper way.

- Rod

JuiceBox

More Photos

Thanks for all of the input everyone.



I looked at all the radiators in the house...they all have the same valve rigging underneath (type/orientation). I've attached a picture of a radiator so that you can see a representative radiator. I mostly have this style in the house...there are a couple of newer cast iron baseboard radiators that were put in during remodeling in the 80s, but I imagine the others are original? You all would no better than I would. The house is late 1930s.



Rod - I've also attached pictures of my boiler setup. It is a Weil McLain P-468-8T.

Jamie Hall

Good heavens...

It never occurred to me that someone might have tried to hook up the union end of a valve to a threaded pipe.  What a dreadful idea.



I'll stick with my original thought -- that the valves in your installation are set up with the union on the riser, and that the valves are screwed directly into the radiator.  Especially since you say that the other radiators in the house -- which don't leak -- are set up the same way.



Only one way to find out: unscrew that union nut and pull the joint carefully apart and see what you have.



By the way -- be sure that the boiler is off when you do this... hot steam burns!



And good luck!