I Have a lot of Classic Steam Problems

PennsylvaniaPete

My name is Pete and I am cold.



The house is a 100 year old Victorian twin.



One pipe system. Oil-fired. Feeds 11 rads (used to be 12, one deleted).



My symptoms are uneven heat, some minor knocking and ticking and burner short-cycling. I also think I'm burning way too much fuel. The two rads at the end of the long run never get hot, not even close. I read “We Got Steam Heat” and I’m working my way through “The Lost Art of Steam Heating.” Every time I turn the page I find a new problem with my system.



My near-boiler piping, as you will see, is wrong in several ways. The system takeoff is incorrectly located, it’s uninsulated, and it’s copper.



There are no vents on the main. I’ve removed the insulation where I believe the vents should be and I can find no evidence of any current or past venting mechanisms. And at the end of the long main run, the main goes into a tee, which is connected to the wet return and a riser. There is no main piping “after the last radiator” where I could put a main vent.



This leads me to believe my piping was altered at some point, probably in the 70’s. (WHY, WHY,WHY?) My suspicions were bolstered when I took a look at my neighbor’s setup and saw that his was different. You can see what I mean in the pictures and the diagram.



From what I’ve read, having no main vents is a common problem. What I’m struggling with is that I can’t find any place where a main vent once was. So where should I put ‘em?



So I guess I have four major questions:



1. Can I add main vents in the highlighted locations?



2. Could my situation be improved by adding “top-of-riser” vents, as Dan mentions in Chapter 8 of TLAoSH? My understanding is that they are not really alternatives to main vents but more supplemental, am I correct?



3. Does anyone have any recommendations for radiator vents? Currently they are all fitted with Vari-Valve Quick Vents. They do not appear to be very old, but I read on this site that these vents can be damaged by too-high pressure. Is that correct? Until recently, my pressuretrol was set to cut-in at 2.5 (NOT BY ME!) with a differential of 1, so I’m thinking these vents should be replaced. The vents on my ice-cold rads feel like (even though they’re open all the way) there is never any air coming out at all. Could they be broken?



4. I plan on re-piping the boiler next spring. Should I insulate the incorrect piping in the meantime?



Of course, any advice or recommendations of any kind will be greatly appreciated. Thanks very much for taking the time to read this.



-Pete

Boiler wrestler

Many problems

You seem on top of your troubles, and are on the right track. For short money and quick results I would lower the pressure, skim the boiler, replace radiator vents with Hoffman #40 and see where that takes you. Next would be adding main vents and the locations you suggest seem like a good place. For your near boiler piping, insulation can't hurt and if it makes you feel better that is far from the worst piping job I've seen.

Rod

System Problems

Hi Pete-

   I wouldn’t spend  too much time comparing your piping layout with your neighbor’s as duplicating your neighbor’s  isn’t necessary to achieve a working system even though the house plans may be similar.

 

We need to know more about your system. When you take pictures take them from back away so see are able to trace out your piping. How many steam mains do you have?  Are any of the radiators getting hot (even warm) ? Have you a skim port on your boiler and has the boiler been skimmed?   Take some more pictures of the boiler from different angles and include the return and piping around the boiler.



Thoughts:

1.The present header configuration has the riser to the steam main coming off between the two risers from the boiler . This cause the two steam streams from the boiler to collide and produces very wet steam.  The steam piping on the boiler needs to be reconfigured.  If you boiler hasn’t been skimmed skimming it might help too.  Looking in the water sight glass on the boiler what is the waterline doing when the boiler is running? Much motion up and down?



2. Pressure - the maximum pressure of a residential steam system should not go over 2 PSI.  It sounds as though someone in the past raised the pressure in a mistaken approach that raising the pressure would heat up the radiators.



2. Vari Vents cause more problems than they cure. They were improperly installed to try to cure the problems caused by the lack of main venting. I would replace them with radiator vents which have a much smaller venting capacity.  An old steam heating adage- “Vent your Mains Fast and your Radiators slowly!” 



3. As you have already concluded  your system needs  main vents. A rough drawing of your system would help out along with the length of the mains and pipe sizes.  As for location of the main vents -(going away fro the boiler) either just after where the last radiator lateral comes off the main or on the dry return before they drop down to floor level into the Wet Return.  It looks like that in your pictures a radiator lateral comes off the end of the steam main. In that case put the Main vent before the end of the main and use a slightly larger radiator vent.



4. As to the “top of the riser vents” - I would let that go at the moment. You will probably find that adequate main venting is all the is necessary in the venting compartment.



5, Insulation- At this point I wouldn’t  bother.



Main Vents and radiator vents can be got at your local heating supply or from Pex Supply on the internet.  Let us know the size of your mains and we can calculate how much venting you need.

Have you measured the EDR of your radiators? I’ve attached a form which helps you do this . Knowing the EDR of each radiator helps determine what size vent that radiator needs.

- Rod



 

mcsteamy

Thoughts...

I think it probably goes without saying, but be smart if you touch the insulation.  It may contain asbestos, so you have to be careful.  Use a glove bag, a respirator, and other proper protocols for safely removing asbestos if you insist on doing it yourself.



That said, vent the mains first and foremost.  Putting a bunch of tiny vents on the system is only going to waste more money.  The Varivents actually work just fine if you use them properly.  On a cold radiator with a long run-out or riser they can be just the ticket.  If you have no main vents, they can also work great if installed at the end of the run.  I have a couple of them installed that way, and they are invaluable tools.   If you have then on a whole system, you don't need to remove them unless they fail or spit.  The key is TURNING THE OTHER VENTS DOWN TO "CLOSED" or darn near to it.  So throttled down, it is a very reasonable vent.  Personally, I love Varivents because they are easy to adjust with a massive adjustment range.  If I'm going to be in a room for a period of time and want great heat, I just crank open the slider, and close it when I leave.  (NB:  At 2 oz, a Varivalve vents .16 when closed, about the same as a Gorton 4.  Half open, it vents like a Gorton D.  Full open, it vents half as much as a Gorton #2 (or equal to it, if Heat-Timer is to be believed).)



To vent mains, you can just drill and tap off the top of the main at the end.  If you want, use a straight pattern Heat-Timer or a pair of them.  How durable they are, though, is a matter of dispute.   A Gorton #2 would be better.



The pressure should not have killed the Varivents, but it sounds like to you already know to CRANK IT DOWN. 



You can insulate the piping using regular old R-13 fiberglass with paper backing.  I've done it, and it worked for years.  I wrapped it all with a nice foil duct tape.  You might not even need to repipe the boiler if the venting fixes your problems, and wet steam isn't a major issue.  There are a lot of these in service and working "okay" (if not perfectly).  Then again, many never work right.  If the copper starts leaking, well, then it's time to replace.