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Jamie Hall

Jamie Hall

Joined on September 16, 2002

Last Post on July 27, 2014

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A good place to start

@ October 26, 2009 12:37 PM in boiler water line

if you don't have them is Dan's books, available on this site (I sound like an advertisement... but they really are worth it!).  That said...

A very common problem in the type of retrofit you did is that water line.  It is not at all unusual to have the end (or sometimes elsewhere) on the steam mains drop to a wet return, and to have the ends of the dry returns drop to the same wet return.  If the water line is too low, there is no water seal between the to and steam gets into the dry returns -- presto, no heat.  The easiest solution, as you note, may be a false water line, since it sounds as though putting the new boiler up so that the water lines would be the same would then require a ladder for servicing!

Second, there should be no need for a vent on a two pipe radiator, although it won't hurt anything.  The air and condensate should go out -- usually through a trap, but sometimes through an orifice or other seal -- into the dry return; the air then goes to a main vent, and the water back to the boiler.  If the return from the two pipe radiators is yeouch hot (not just warm) you may be getting steam into the return through the radiator, which is another way to shut down a two pipe system.  Depending on the type of system, you may need to throttle those radiators which offend, or replace the trap or whatever to bring them back to design.

A one pipe radiator which doesn't heat isn't getting steam (yeah, I know, that's one of those remarks.  Oh well...).  Either the air isn't getting out -- bad vent -- or there is something, such as a sag or a badly pitched pipe -- which is letting condensate block the flow.  Or even a bad valve!  Or one which doesn't belong.  I would trace out the riser to those radiators when the system is running, and see how far along steam is getting -- that may produce a hint as to what's wrong.  Same sort of logic applies to a two pipe radiator, except for the vent.

Do not check a one pipe radiator's vent by removing it when the system is running -- if it is the vent, you'll get steam out of the resulting hole, which can burn very badly!  Also removes wallpaper...

Check your system pressure -- no more than a pound an a half, and less (say 10 to 12 ounces) is better, if your controls will let you do that.

Just a few thoughts -- by no means exclusive!

Er... blurp

@ October 24, 2009 6:06 PM in Where Did My Water Go?

losing that much water sounds to me like a honest to gosh leak in a wet return.  Under the carpet.  Under the concrete.  Sob.  Without knowing exactly how your system is hooked up, I can't suggest the best way to find it... maybe someone else has a bright idea?


@ October 24, 2009 6:02 PM in vaporstat

L408A, break on rise

Not normal!!! TURN IT OFF!!!

@ October 24, 2009 3:34 PM in Steam heater

Be happy that your pressure relief valve is working properly, because something else most assuredly isn't.  A residential boiler should never, ever go over a few psi (most fittings, valves, etc., are rated around 3 psi, with a never exceed of 10).

TURN OFF THAT BOILER NOW, with the emergency switch, and get a pro in there, pronto, to find out what's wrong.  I do not want to sound alarmist, but if that safety valve happened to stick shut, what you have could launch your whole house into low orbit.

I'd stay

@ October 24, 2009 3:29 PM in Stay with one pipe ?

with it.  One pipe steam is a very very good system -- easy to maintain and very good even heat.  I would not be too concerned about the steam pipes.  Mine are over a century old now, and the only one which has given any problem at all is a wet return which was unused for some years.  Everything else is completely sound.  Steam pipes and radiators do rust, but only very very slowly.  Do NOT, however, attempt to pressure test the system.  It wasn't designed or built for pressures over a pound or two!

Even if you were to run the pex yourself, going to hot water will not be a zero cost option.  There may be a very small increase in efficiency for a hot water system -- if, and only if, you are using a very high efficiency mod-con boiler with all the bells and whistles.  Otherwise, no.  The increase is minor (at best, for a system using 1,000 gallons of oil a year, you might save as much as 87 gallons if you were really fortunate), and you will never pay back the cost to run the pex.  Nor, in my humble opinion, will you get more comfort, once you get the steam system running properly (it's likely that it needs tuning -- you do have Dan's books, don't you?).  A good steam system is the Cadillac of systems!

While replacing the boiler, you can probably figure out a way to pick up a new radiator (steam) in the attic without too much trouble.  Ideally, obviously, the new riser would be iron or steel.  However, in a pinch and if you don't mind the odd expansion noise, you can use copper.  Just make sure that it is free to expand, and that it can expand in such a way as to not twist any joints if at all possible.  The basement, if it needs heat, can be heated with a hot water loop off the steam boiler.


@ October 24, 2009 9:58 AM in Help Please with Piping and Pickup Factor for Unusual Setup.

the boiler itself, and the heat loss through the insulation (there always is some) the basement will probably be warm.  Whether it will be warm enough for you, I wouldn't care to say -- but if it isn't, you'll get much better results with putting in a deliberate heat source (lots of options) than depending on uncontrollable heat leakage from your steam pipes.

There are a number of options for insulating fittings like elbows and T's and unions and the like, depending on the type of insulation one is using for the pipes.  Some types have prefabricated covers.  Some types one can make a cover rather easily by cutting and joining the insulation pieces, or pieces from a section the next size up.  Just depends on what you are using and what's there -- and, often, your ingenuity.  The fiberglass and duct tape works, but it does tend to look a little tacky!  The insulation doesn't have to fit glove tight around fittings, although the tighter the better, of course.

Can't compare

@ October 24, 2009 9:51 AM in Pipe slope

sanitary waste drains with steam lines.  Apples and oranges.  The code requirements for sanitary waste drains are indeed there so that if there are solids, the velocities are high enough to move them.

The pitch for steam lines has been determined over the years -- more than a century -- to be adequate from the condensate to flow properly.  Note that counterflow has twice the pitch of parallel flow (and also note that a counterflow steam main should be a larger diameter).  If the pipes are installed and hung properly, no water should remain in them.  That's a big if: you would be astonished at how often I see both mains and returns with sags.

The consequence of not enough pitch is that condensate may not drain properly.  This may produce water hammer (sometimes quite spectacular water hammer) or even, in some really bad cases, no heat at all as the water sits there and the steam (or air, on a return) can't get by.

Not that uncommon

@ October 24, 2009 9:45 AM in Half Heated Radiators

to have some radiators heat only half way -- or less -- depending on how long the system has been firing and how big the radiator is and where and so on.  The real question is, if the system fires for a long time (long enough to start shutting off on pressure), do the radiators heat more?  If so, it is likely that additional venting either on the main feeding them (two pipe) or on the radiators themselves (one pipe) might help.

On the other hand, this may be quite normal -- hard to say without knowing more about the situation and circumstances.


@ October 23, 2009 7:51 PM in Capping off a Steam Pipe?

well, no -- though I've seen worse.  But no, you don't have to take the valve off.  What you've done is fine.

Wonder how much your superintendent could save if he maintained his system properly?  Sigh...

Most boilers

@ October 23, 2009 4:07 PM in Help Please with Piping and Pickup Factor for Unusual Setup.

have an EDR rating as well as a BTU rating; check both.  You're certainly on the right track -- except for one thing: those uninsulated mains in the basement.  You will get quite adequate basement heat after they are insulated.  But -- if you don't insulate them, you may have -- in fact, are rather likely to have -- some serious balancing and water hammer problems, because what happens is that a good bit of the steam will condense in the mains, rather than condensing where it belongs, in the radiators.  I have heard of situations where one or more radiators at the end of longer mains never got heat at all on normal runs, because the steam never made it past the uninsulated main.

Bottom line: get some good (preferably 1") fiberglass insulation for steam pipes --  it's easy to put on and install it.  You'll be a lot happier in the long run.

If you do, then your 1.33 to 1.5 pickup factor should work fine.  If still don't want to insulate, you should treat those exposed mains as radiation, and add their square footage in -- and then add the 1.33 to 1.5 pickup factor.

I might add that water hammer etc. problems are much less likely to be caused by oversizing a boiler -- unless it's really grossly oversized -- than they are by either poor near boiler piping -- or uninsulated or improperly pitched mains.

I know just what you mean!

@ October 23, 2009 3:56 PM in cast iron fin tube in steam systems

It's annoying to have a system which is supposed to work one way, working but set up more or less 'incorrectly'!  Been there...  The main line air vents you will need -- after all, the air has to get out of the pipes somewhere! -- but in a two pipe system, you should't need the vents on the radiators -- although, as you note, they won't hurt anything.  Just not elegant.  Suspect you're right on the service man gettng carried away...

You say there are no traps on the radiation?  Or is it that they aren't working?  Or does each radiator go to a wet return?

Keep the one pipe steam

@ October 23, 2009 11:28 AM in one pipe steam system ,boiler replacement

but do get the books from this site ("A Steamy Deal") as you may find that your system needs some tuning and maintenance.

There are a number of very good gas fired boilers out there; the main thing in picking a boiler brand, in my humble opinion, is to get one which is sold and serviced by a local professional whom you like and can deal with, and then make sure that it is installed and piped correctly.

If you are fortunate, you may find a professional who does steam (try find a pro, on this site).  If not, educating a professional isn't that hard!  And sizing a steam boiler is really easy: it's done on the basis of the installed radiation in the building, not on the building heat loss, so it's a matter of going around and adding up what you have in the way of radiators, and figuring the load from that (the books mentioned above will help with that).

That old boiler doesn't owe you anything, nor does the burner -- which sounds as though it may have problems anyway.

Only comment I'd have

@ October 23, 2009 11:23 AM in Insulating floor of a 3-season porch

is that Icynene, though an open cell type foam, is air and moisture impermeable -- and seals uncommonly tightly.  Which is part of what you want.

Here we go...

@ October 21, 2009 8:07 PM in STEAM HEATING PROBLEM

The Hoffman return trap was a neat way to avoid flooding the dry returns without having much headroom.  You have to give a lot of credit to Simpson, the guy who invented it.  Here's the library link: [url=]
Clever, those Hoffman guys (the system in the building I superintend has a big Hoffman differential loop in it -- another one of those clever contraptions.  I'm still not sure exactly how the thing works -- but it does.).

Anyway.  Back at the ranch -- I still think a nice Gorton somewhere handy will do the job for you.  Without hurting anything.


@ October 21, 2009 7:21 PM in STEAM HEATING PROBLEM

The Gortons are air vents -- but they are also, unlike the Hoffman you have, vacuum relief vents.  The condensate should still return without trouble, unless I have completely misinterpreted something (which is always possible...).  Vacuum systems were wonderful in the days of coal, when the boiler could still keep creating steam at lower temperatures under a vacuum, but they didn't rely on the vacuum to pull condensate back to the boiler; they were still basically a gravity return system.

Let me go check the Hoffman catalogue here (it's in the library) for more infor...

Certainly sounds

@ October 21, 2009 7:15 PM in Steam Rad Problem

as though something is trapping water somewhere, but it isn't likely to be the radiator itself -- although a little more pitch to the return probably wouldn't hurt.  Is there a horizontal bit somewhere in the return line which might have gotten pitched backwards?

This sounds like one of the systems for which the steam into the radiator was controlled by an orifice or other restriction on the inlet or outlet.  Did that get changed?  Or?

It does sound

@ October 21, 2009 2:27 PM in STEAM HEATING PROBLEM

as though as the system is cooling that somehow air is having trouble getting back into the mains and returns.  A true vacuum system (rare, these days!) has vents which do not let air back in -- or at least not much to speak of.  But, the air having been vented out when the system starts, it has to get back in when the system stops.

What changes in the venting were made when the new boiler was put in?

One approach which might solve the problem pronto would be to find a handy spot on the dry return where you can stick a Gorton #2 and put it on -- can't hurt anything, and might just get rid of the glug...

As they say locally

@ October 21, 2009 2:19 PM in Please help me with my steam heat system for a 3-story building!


First off, your pressure is too high.  Try setting the lower pressuretrol to around 1.5, which is as low as it will go reliably, with a differential of about 1.  The way it's set now, it's possible that it will never turn back on, once it's turned off.  The one with the reset button can be left alone for the moment; it's there for safety.  You can veryify that the pressuretrol is working the way you want by turning the system on with a high setting on the thermostat; unless you have a really bad leak somewhere (or the boiler is badly undersized) eventually the pressure will begin to rise and you will see the mercury switch begin to tilt.  It should tilt over, and the burner should stop.  Then gradually it should tilt back, and the burner start again (I love the old p'trols where you can see what's happening!).  You shouldn't see the round dial (pressure gauge) move much, if any.  If you see the gauge move beyond 2, or the boiler is shut off by the other p'trol, the one you're playing with isn't working, and that will need to be fixed -- the sooner the better.  Let us know.

The various comments on insulation are right on the money -- that 45 foot uninsulated main could well be what's killing you, particularly it it is the one that feeds part or all of the third floor (you didn't menton).  1 inch of insulation is enough, though.

in my humble...

@ October 21, 2009 9:54 AM in How close to boiler to insulate pipes?

opinion, if it's hot, insulate it -- unless it's just too darn complicated to get the insulation around!  Then it's not worth the effort...

I might add

@ October 20, 2009 3:47 PM in STEAM HEAT PROBLEMS

that if you have to refill the boiler often -- even as much as once a week -- you have a leak somewhere.  That's a separate issue, but you should find it and fix it.

Steam heat

@ October 20, 2009 3:46 PM in STEAM HEAT PROBLEMS

by itself is very unlikely to cause a respiratory problem, except very rarely new paint on the radiators can -- but that you would smell, for sure, and you don't mention that.

Low humidity can cause or aggravate some types of respiratory problems; as Nick said, get a good hygrometer and see where you are.  If it's dry, the guys have it -- pans on the radiators or a good humidifier.  And keep it clean.

If the problems began after you moved into the house, there are so many other things which could be the problem -- and are much more likely to be the problem -- you may have some difficulty finding out what's what.  Good luck!

sized and pitched

@ October 20, 2009 3:41 PM in Mixing counter flow and parallel flow

correctly, don't see why not.