Steam stumper, need input...

Timco

2-pipe steam, about .5lb. Main leaves the boiler, makes a loop around the basement, tee's off and heads back to boiler and ties into wet return with a main vent in ceiling. No header, no main drip, I am thinking the main heading back to the boiler (with good pitch) IS the equalizer. Come to find out, all rads heat half way, and it takes 40 min for this to happen. No hammering. I crack a trap union and water slowley drains, but no real pressure whatsoever. Rad heats more than it did, but not all the way across with trap totally disconnected. I am thinking traps in bldg (16) have failed closed, but that would not explain why no steam when trap is removed. Gauge bounces at just under 1lb, and boiler is making steam, as main is HOT all the way around the loop and back to the boiler to the vent. If I remove the vent from the dry return, absolutely no air movement at all. Even if these traps crapped out in the closed position, why no pressure when trap removed?

Tim

Unknown

Just a thought Tim,

is it possible this main vent is too fast for the runouts to the rads?
Sounds like the main is getting steam OK, just not spreading-out well.
I seem to remember Gerry & Steve mentioning a similar problem in their E-book.
Just a thought.

Dave

Timco

I used a Hoffman#75, which is about half of a Gorton #2. Even if it vented the main quick, why no steam pressure through the rads or air movenent in the return? I am pretty sure most traps are stuck closed, but not one rad in the building heats all the way across. 3 rads have new traps, and they do better, but not hot 100%. Seems odd...

Tim

Unknown

Well another possibility,

could someone have installed orifices, but left the traps?
We never know what we inherit from the previous fellow.
What if you plug this main vent completely?, will steam enter the first few rads then?
I would think it should, especially with the trap outlets undone.

Dave

nicholas bonham-carter

direct return trap

some discussion on this trane direct return trap here

http://forums.invision.net/Thread.cfm?CFApp=2&&Message_ID=364563&_#Message364563

and.....

http://www.heatinghelp.com/pdfs/26.pdf

are you really sure of the pressure with those old pigtails?--nbc

Timco

I did not check for orifices. I have only seen those on HW systems. I can remove the rad from the valve and see if I get steam that way. As for the trap, it ties into the dry return about 6 feet away from the boiler in 1/2", and has a small 1/2" check valve, but has been disconnected at the boiler side for some time. I thought that was the vent before it was vented by a main vent.

Tim

Unknown

Good notes NB-C,

but even if vapor, should it not(the rad), receive steam with the trap undone?

Dave

Unknown

That CV

was likely detrimental to this Trane system,, I would doubt its in use now.
Sounds like someone tried some system changes that didn`t work, and now your to figure it out.

Dave

RonWHC

Input may be just what

you need. I see a very old in-shot gas burner in a very old boiler. I might be tempted to add some btus & see what happens.

Doubt traps have all failed. They may just be setting there, open, waiting for some steam to fill the radiators - so they can do their thing.

Timco

well, I thought I was doing fine when the main loop heated well and I could hear the main supply vent doing it's thing, but nothing going through the rads. The boiler is making steam, this I know. I will try some more pressure but I did get better results without the rad trap. The traps are Trane from about 1900. Rads with new traps do best, but not really totally hot. My guess was all stuck shut. They are after all 110 years old. I would not doubt for a minute they all are bad, but with 3 working traps, I should get some air flow off the dry return after removing it's vent...but no air, nada.

Tim

Unknown

I agree Tim,

but raising pressure is not the answer(unless originally sized that way), something is keeping the steam from those rads, and unless the traps have failed closed I see no reason for-it.
However, as I said, with the traps open it should get hotter than heck!

Dave

Mark Eatherton

I'd try...

turning it DOWN (pressure) first...

Maybe the gauge is bad and you have 5 pounds instead of .5 pounds, and the traps are having a problem opening against that pressure.

Just a guess on my part.

ME

Timco

Good idea. Gauge was replaced last season I was told, but I planned on bringing a gauge I keep on hand to check it. Even if I had 5lbs, if I removed the trap, it should REALLY heat up, no? I am always VERY cautious loosening steam fittings while the heat is on...really seems like no pressure.

Tim

Steamhead (in transit)

Maybe the old snowman

has a steam leak into the chimney. Do they have to fill it often?

Another possibility is the Direct Return Trap has failed and steam is pressurizing the dry return thru it. Though that wouldn't explain why nothing comes out of the dry return vent........

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Timco

They do have to fill often, but the main supply vent was stuck open with steam shooting out all day & night. Waiting to see how often fill is needed now with good vents. When I go back, I will try flooding it. My hope was the bad vent was where the water was going. I need to vfy I can make pressure and get steam out of the rads. Every trap I broke free let out a lot of water, then a bit of spitting...then nothing.

Tim

Timco

duplicate

Steamhead (in transit)

That can kill a boiler

and besides, replacing that snowman could cut their gas usage in half. One of my Dead Men's Books says these things were only good for about 40% over-all efficiency on oil, and I'd expect about the same on gas.

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Dave Stroman

A couple of thoughts.

See if you get steam at the valve, not the trap.

Maybe the boiler is so undersized that the system piping and rads condense most of the steam before the traps can get very much. Clock the meter and compare with the EDR.

Does the boiler cycle on the pressuretrol?

With no equalizer, could the pressure in the boiler be pushing the water into the return?

Seems like there is some constipation somewhere.

Dave Stroman

Timco

Flooding or stuck open vent? I would only flood a cool boiler to check for leak...seems harmless. As for replacement, the gas bills are actually pretty reasonable compared to HW snowmen, which could point to underfired. I will clock the meter. She wants to make it work right, but cannot afford a new boiler and I believe her. Inherited building with major issues. I did try opening system at valve and felt like really hot air, not steam. system is not very big, just a 2" main. End of main becomes equalizer. I think I need pressure as this is not a vapor system. May just be too low but I did not have much time today. Thanks for all the input!

Tim

nicholas bonham-carter

solving steam problems

this is why you have to live with the system for a few weeks, before you get to the bottom of the mystery.

i wonder if it might not be that sort of vapor system whose parts will not function above 2 oz.

only way to check is to start removing the closest radiator from the pipe to see if you have steam, and go on from there.--nbc