water loss in EG furnace

joecann

My daughter has a weil mclain EG 30 1 pipe steam furnace in her house.  Under normal  heating conditions, she needs to add water ever 1-2 weeks.  The problem is when it gets really cold out and the low water cutoff kicks in after 8-10 hours.  Despite repeated attempts to adjust the pressuretrol, the furnace runs up to 5 PSI, the is at the lowest pressure setting.  It has dry returns and no leaks that I can detect.  I am tempted to get an automatic fill valve, but I am not sure if this is a dangerous bandaid.  Any help out there?  Thanks

Steamhead

Might be a leak above the waterline

in which case the boiler is toast. Here's what one looks like:



http://www.heatinghelp.com/forum-thread/135685/Another-rotted-out-atmospheric-steamer-replaced



Where is your daughter located? There should be a good Steam Man near her.....

Hap_Hazzard

It sounds like the pressuretrol isn't working

most likely because of a plugged siphon (pigtail). If the system doesn't cycle on pressure she could be losing that water through the vents.



Since there could be any number of things, and because the pressuretrol will need to be readjusted, it might be a good idea to bring in a good steam technician to diagnose the immediate problem(s), inspect to see if there are any other looming issues, and make any needed adjustments. Has she had the burners adjusted recently? The flueways brushed? Taking these steps before heating season can often pay for itself in fuel savings, and if there are more serious problems, it's best to find out while the days are still long and warm.



Oh, and the auto filler: they are a nice addition, but they are not a cure for a problem like this. In fact, as any of the pros here can tell you, they often hide problems like the one you are describing, causing homeowners to delay getting service and resulting in more serious problems. The reason for having an auto-feeder is to keep the heat on if a major leak develops in the piping. You'll get water on the floor but at least it won't freeze. If you're maintaining your system properly, the auto-feeder should never come on.

joecann

reply

The furnace had a single pigtail on it, which was plugged.  I replaced that one with individual pigtails for each item (1 pressure gauge and 2 pressuretrols).  I adjusted the pressuretrol to its lowest points on the scale and the pressure gauge showed that it ran until 5 psi, then kicked on again at 1 psi.  it was hard to tell exactly, because the range of the scale is so high.  I replaced the gauge and got similar readings.  I looked for a lower pressure, better resolution gauge, but all I could find were ones rated at 175 degrees or so.  I was worried that 212 degree steam would damage the gauge.  Anyway, I wonder if running the furnace at a lower pressure could reduce the water loss. 

I am an engineer by training and career and a terminal do it yourselfer.  I had been doing energy audits of multifamily buildings in NYC and became interested in steam systems.  Read Don's book and jumped at the chance to work on my daughters steam furnace after she bought a house in scranton, pa a few years ago.  I rebuilt the water level float, remounted the controls, replaced the relief valve, insulated the steam pipe, increased main vent capacity and replaced radiator vents to balance the system.  The water loss is the last problem, and i hope it doesnt mean that we have to replace the furnace.  I am willing to replace the pressuretrol with a vaporstat if lower pressure operation would help this problem.  even if it is a leak that can be lived with, the loss has to be less at a lower pressure.  Velocity and flow through an orifice vary as the square root of the pressure, so operating at 1/5th of the pressure would result in 45% of the flow. 

Hap_Hazzard

Okay

Now that we know who we're dealing with... :-)



Yes, reducing the pressure should help reduce the leak, whether that water is escaping as steam through the vents or as water. The pressuretrol should not be letting the pressure rise that high at its lowest setting. With a .5 cut-in and a differential of 1, it should cut out at 1.5 psi. If you've ruled out any obstruction in the pigtail, the pressuretrol is shot. Those micro switches aren't that great for accuracy anyway but before you run out and get a vaporstat' let's talk about this leak.



Do you remember noticing any "spitting" from the vents, or did any of them continue to hiss after the radiator got hot? Are there any parts of the return or supply piping that are out of sight, where a leak might drain into a sump without notice?



If you can rule out all of the above, I'm going to have to agree with Steamhead.



When you get a leak above the waterline, you don't get a puddle on the floor. You just get a somewhat larger, whiter plume of water vapor coming out of the stack. The steam leaks out under pressure into the combustion chamber where it's superheated and sent up the chimney. These leaks are very hard to detect except for the obvious, and increasingly copious, water loss.



I'm hoping this isn't the case, but, unless you've missed something, it doesn't look good, and if it is, you don't want to put any more money into this boiler. The upside is that you have enough time to find out for sure and shop for a new, more efficient model before it gets cold.

Steamhead

That's true as far as it goes

but if the boiler has a leak, it's only gonna get worse. It's only a matter of time.



Scranton, eh? That's steam country- but there isn't anyone showing in that area on the Find a Contractor page. Anyone in the Scranton/Wilkes-Barre area want to jump on this?



If you need some more eyes on this thing, get in touch. Baltimore is only a few hours' drive from Scranton, Olde Good Things is always an interesting place to visit, and I-81 gets real pretty this time of year.......

Hap_Hazzard

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Hap_Hazzard

If you are up this way

I hope you can stop by King of Prussia for an hour or two. I'll show you the drop header I'm building.

nicholas bonham-carter

Finding a boiler steam leak

If you turn off the boiler, and overfill it above the section top, the leak should show itself as a dribble into the combustion chamber. An extension pipe in place of the relief valve would give you an easy to see level above the boiler. If the water was at the top of the pipe at night, and the next morning was lower, then there is probably a leak in the sections.

If there is a leak, then you may be able to get replacement sections, and install them.

If the cost of a new boiler is not much greater, then a replacement would be better.

Do a survey of the radiators to determine the correct size needed, and do not go by the old boiler.

With a proper pigtail, the steam will never reach the low pressure gauge (gauge store.com. 0-3 psi).

If you can post some pictures of the piping, we can see if there is something which should be changed at the time of replacement.--NBC

BobC

Double check and low pressure gauge vs steam

i agree with everything that has been said about testing for a leak in your boiler, you have to determine if there is a leak before going to far down the road.



If you isolate a low pressure gauge with a pigtail and fill the loop in the pigtail with water before screwing on the gauge it will NEVER see steam. My gauge never gets above 120 degrees.



What model pressuretrols are being used here and are they the differential types? Verify that they are wired in series - one never knows. If they are mercury bulb types be sure they are level and that the loop in the pigtail is such that they don't change orientation significantly from side to side when hot. Ones used for residential steam should go down to 2PSI and the older PA404's went down to 1.5PSI.



Bob

joecann

eg leak?

Good olde things is a great place and scranton is their headquarters.  I have also been to their stores in NYC.  I love that salvage stuff.

I will be sure to give you a holler if you are willing to come to scranton.  I will check first for the presence of a leak.  I will be back in scranton in a few weeks to do that.  I have a salty old plumber type who will help me put a new furnace in,   this is some thing I have been wanting to try.  I installed a gas hot air condensing furnace a few years ago in my house, but would love the challenge of a steam furnace.  The timing is just not right so i would like to know how I can extend the time left for this furnace.  Is there any chance we can live with this for 1-2 more seasons?

joecann

eg leak?

Good olde things is a great place and scranton is their headquarters.  I have also been to their stores in NYC.  I love that salvage stuff.

I will be sure to give you a holler if you are willing to come to scranton.  I will check first for the presence of a leak.  I will be back in scranton in a few weeks to do that.  I have a salty old plumber type who will help me put a new furnace in,   this is some thing I have been wanting to try.  I installed a gas hot air condensing furnace a few years ago in my house, but would love the challenge of a steam furnace.  The timing is just not right so i would like to know how I can extend the time left for this furnace.  Is there any chance we can live with this for 1-2 more seasons?

joecann

EG water loss

I am just leaving scranton now and wont return for a few weeks.  I am planning on testing for a leak when I go back.  I know the pressuretrols were wired in series and I set it up to run to the lowest pressure, but it never shut off util it reached about 5 psi.  

as soon as i test for leaks I will be back on here to get an idea of next steps.  thanks 

nicholas bonham-carter

The next steps

Finding a good steam professional might be the most important first step to take. The sooner the leak test is made the better. I don't know when your first frost date is there, but you will need some time after the test to digest the results. These jobs are not an overnight arrangement.--NBC