Excited newbie to steam heat, bunch of really longwinded questions (with photos!)

geoff27

Hi everyone,



My fiancee and I bought our first house this past September. It was built sometime around 1935, and had an addition put on in the mid-1960s. It's got a gas burning steam boiler (somewhere in the neighborhood of five years old, I think) and single-pipe radiators. As a first-time homeowner, naturally I've become obsessed with the boiler and trying to fine-tune and balance the whole system, learning everything I can about steam heat, and HeatingHelp.com has so far been the most valuable resource for answering questions as I come up with them. That being said, I've compiled a list of things I haven't been able to find answers for here or elsewhere, so I figured I'd ask them on here and see if anyone would like to take a crack at them.



Photo # 1:

It's my understanding that the majority of the air venting should be done by the main vent(s) at the end of the main line, before the air (and then steam) even reaches the individual vents on the radiators. Well, after inspecting the entire system in the basement, I was able to locate a single main vent down there, and it seems to be on the return line, not at all near the end of the main line. The main line comes out of the boiler, and then splits, one branch going to the east side of the house, and the other branch going to the west side, through the foundation wall and under the crawlspace where the addition was put on in the 60's. Both of those branches sort of loop back and have their own separate return line for the condensate to come back to the boiler. The main vent pictured in photo # 1 is on one of these return lines, close to the boiler. My question is: Does that seem right? And should there be one or more additional main vents to help ease the burden of the individual rad vents?



Photo # 2:

It's also my understanding that a mercury-based pressuretrol is supposed to be mounted perfectly level to the boiler, but as you can see in the second photo, mine is not. How much does this matter?



Photo # 3:

These appear to be "extra" valves. The white wall you see behind them is the foundation where the house used to end before the addition was put on in the 60's. Behind that wall is a crawlspace, and that main line and return line go back there and feed a total of four radiators in the addition part of the house. I'm taking a wild guess and saying that the two valves pictured in the third photo here used to feed radiators on the west wall of the house before the addition, and since it was added on to, they just closed off the valves and continued the pipes further. The problem is, during a particularly long heating cycle, when the pressure is at its absolute highest (hovering around 2 PSI), both of these valves leak steam. One of them even whistles like a kettle. So they're not completely cutting off the steam flow, and thus it would seem like they're being wasteful as steam is just escaping into the basement air. My question is, is there any harm in just capping these off?



Photo # 4:

I broke the threaded end of a vent off in the radiator when trying to remove it. There's at least one other post on here in which someone describes doing the exact same thing, and I've been going down the list and trying each method but without success. The radiator in photo # 4 had a vent that was kinda faulty and would whistle and leak steam up into the air (hence all the peeled paint off the radiator), so it was the first one I decided to replace. When I tried to unscrew it, the whole vent twisted itself off, leaving about a centimeter of threaded end still in the radiator. After I attacked that with pliers, all I succeeded in doing was ripping off the remainder, leaving it almost flush with the radiator. Then I tried an easy-out type extractor, which didn't work. The bit left inside simply will not budge, it's like it's completely fused with the radiator. I applied Liquid Wrench liberally all around it, let it sit overnight, tried the extractor again, no good. It just will not move. Now, before I attempt to drill it completely out, tap the hole to 1/4" NPT and use a 1/4" to 1/8" bushing, is there any harm in trying to fit a 1/16" to 1/8" NPT bushing in there, or is 1/16" too small of a passage to allow the vent to do its job properly? I figured I might try that as a last resort before committing to drilling and tapping a 1/4" hole.



Wow, that was a lot of words. If you've read this far and have any suggestions for me on any of these questions, you have my eternal thanks! I can provide more info or pictures if needed.



Thanks,

Geoff

Jamie Hall

Welcome aboard!

See what we can do here...



Question 1 -- in most steam systems -- and yours is no exception -- vents; good big ones; at the ends of the steam mains help. Sometimes they help a lot. The trick usually is figuring out how to pipe them in. This sometimes takes a good bit of ingenuity, and I'd have to have a look-see to say much more.



Question 2 -- mercury pressuretrols have to be set dead level, or they will be way out of calibration. You can probably lean on yours enough to get it level without causing any leakage -- one of the advantages of pipe threads. But it may take some leaning, as you will be actually slightly bending the pigtail.  It's worth doing.  If you are feeling ambitious, you should also rotate the whole pigtail clockwise a quarter turn, so that the loop is perpendicular to the pressuretrol rather than parallel.  This makes a small difference in the accuracy -- if the thing is hard to turn, don't worry about it.  But do bend it enough to get it level.  That will make a big difference.



Question 3 -- capping the extra valves is a very good idea.  On the other hand, maybe you could get the one on the steam main off and install a main vent on it... see Question 1!



Question 4 -- how tiresome.  I think you're committed to drilling and tapping.  Stuff happens...

Hap_Hazzard

Some answers

For the broken vent, if you have a taper reamer, carefully ream the hole until the first couple of threads are visible, then drill through it with a 5/16 (8mm) drill, keeping the dill perpendicular to the radiator tube. Carefully insert a 1/8 NPT tap and try to engage the existing threads. Run the tap in slowly and carefully. The trick is to cut the brass threads out of the cast iron threads. Brass is a lot softer, so it's not impossible. Keep backing the tap out and inspecting the threads. You can usually afford to go a little deeper than the original threads because the threads are tapered.



Regarding the Pressuretrol, the level is only half the battle. The other problem is that the loop of the siphon is aligned with the control. When the boiler is making steam, the loop expands, causing the control to tip slightly. So if you had a unit with mercury switch, you'd want the pigtail to be rotated 90 degrees with respect to the control.



Regarding the old radiator valves, remove the nipples and put plugs in the tee fittings. Use a good thread sealing compound.



Regarding balancing and venting, you're dealing with two common scenarios. First, most steam problems in older homes are caused by the removal of asbestos insulation from the exposed piping without replacement. This can cause somewhere in the neighborhood of 40% of the heat to be lost from the piping, resulting in uneven heating of radiators. Rather than replacing the insulation, homeowners and inexperienced heating contractors try a variety of other approaches like fiddling with venting and cranking up the firing rate, leading to excessive system pressure and dangerous CO levels. The cure for this scenario is to try to restore the system to its original condition, the way the dead men who built it intended.



The second scenario involves the addition. You see some strange stuff when people try to extend a steam heating system into an addition. One trick is to add a runout to the end of a main by removing the main vent, or extending a main and not bringing the venting to the end or not increasing the venting to accommodate the added volume.



There are a lot of people here who can help you, but you'll need to give them a better picture of your system. A map would be helpful (For some examples, look for some of the stuff crash2009 has posted.) or at least details and dimensions. One thing I think everyone would agree with is that your first step, unless you're going to be doing a lot of repiping, would be to insulate those pipes.

nicholas bonham-carter

Insulation important

To the previous wise words, I will add the importance of generous main venting. I see in your picture, insulation under the floor, probably to control the main vent leaking. Replace it and the others with the biggest you can find.--nbc

geoff27

Thanks!

Thanks for the replies everybody! I'm relieved to know I was more or less on the right track with some of this stuff.



Re: Insulating the pipes: Absolutely. Given how much heat is being lost with them without insulation (I had no idea it could be as much as 40%!), and since it's a one-time expense that'll save some money in the long run, insulating them is at the top of my list of priorities.



Re: the pressuretrol: I will see what I can do to level it out. Don't know if I'll be able to actually rotate the pigtail 90 degrees, but I may try.



Re: Capping off the old unused valves, and dealing with the main vent: I'm going to try what you suggested, Jamie Hall, and cap one of the two, and see if I can get a vent on the other one. Much easier than trying to put in any new piping (which I have NO experience with). I'll also replace the main vent pictured in the photo, because who knows how long that's been there or if it's even doing its job.



Re: the broken-off radiator vent: This thing has become my white whale, haha. I think next I'm going to do what you suggested, Hap_Hazzard, and see if I can ream, drill, and use a 1/8" tap to sort of clean the brass out of the rad threads. I can definitely see how brass is much softer than the radiator itself, so I can see how that might work. I'll try basically anything under the sun before I resort to drilling the entire mess out to 1/4", as that's another area where I have no experience, drilling and tapping in metal.



I started putting together a map of the whole system, both as a way to get to know it better, and so I have something to refer to when asking questions in the future. In the meantime I'm going to do what was suggested above, and also insulate as much of the piping as I can! Thanks again for all the replies and info, folks.

Dave in QCA

regarding broken vent

I have had this exact same problem before.  And I can say that with absolute certainty, if you get a 1/8" pipe tap, and also the correct size drill for that tap (the tap package will say), and iff you drill first, it will remove some but not all of the brass part that is remaining.  Use the tap and it will remove the rest and will clean the threads in your cast iron radiator down to the original surface.  Don't sweat it, this one is easy.