Is my Weil-McLain EGH-95 dead? Replacement advice requested.

winter_is_coming

Hi! I am located in Louisville, Kentucky, and I don't have a lot of confidence in any of the people who have serviced/diagnosed my Weil-McLain EGH-95 boiler. I need to take matters into my own hands. I am a quick study, but I didn't know how much I didn't know about my boiler until I came to this forum. Please excuse my ignorance; I promise that I am willing to learn from any advice that I am given from this forum.

My husband and I inherited this boiler when we purchased our house from a foreclosure sale two years ago. The boiler was in pieces and we had a couple of local companies come out to bid on reassembling it. The burners were all thrown away by cleaning crews (the previous owner was a hoarder), so we had to purchase all new burners. In all, we spent over $3k to get it running for the winter of 2013. Even when it was running, the radiators that were farthest away from the boiler never got warm. That end of our house was always very cold. We had a technician perform seasonal maintenance for the winter of 2014 and the boiler seemed to function the same as it had in 2013. Fast forward to yesterday when we had another technician come out to service it for this winter. He told us that it probably has a crack above the water line and that we need to replace our boiler. We had a second tech come out and they said that it can be repaired, but it would probably cost only slightly less than a total replacement.

Here's my issue--If I can't trust these people to properly service my boiler, how can I trust anybody to install a brand new one? And how do I know that the new one isn't going to fail for the same reasons as the old one (still unknown)? Presumably the person who reassembled the system in 2013 (who is the only Weil-McLain authorized rep in our area) should have noticed problems that would lead to complete failure two years later, and the person who serviced it last year should have noticed problems that would lead to failure. Now our backs are against the wall because winter is getting here quickly and we need to make a very expensive and very complicated decision in a short amount of time.

Here's what I know (which isn't much):
-I am attaching a photo of the corroded area where a leak has certainly occurred.
-One of the techs yesterday filled up the tank and water came out of the second section from the right side. Water also bled out from several areas between sections.
-A guy is coming out tomorrow to measure our house for a new boiler. He said that he is going to need to look at all of the radiators, so I think he will also be doing an EDR calc. I'm going to do my own when I get home today so I can ask educated questions.
-We have really hard water in Louisville and we do not have a water softener.
-From this forum, I now know how to clean out a boiler. We will do that in the future frequently. We have not done it before.
-When the boiler was working, we noticed that water seemed to be pumping into the system a lot. Our techs weren't concerned with our concerns, but we thought it was too frequent. We also never saw any puddles under the boiler, so we didn't think that it was leaking out any water.

Sorry for the novel. I need some help troubleshooting to determine if our system is beyond fixing, and if it is, recommendations for how to identify and install a new system that will hopefully not fail in a short amount of time. I'm happy to answer any and all questions. Thanks!

vaporvac

I feel your pain. You need a new boiler and that didn't happen overnight or probably since you've lived there. It's hard to believe they took your money to put that back in even as a stop-gap measure. We don't really discuss pricing openly on the forum, but I'm surprised they didn't apply that to a new more efficient one.

Your installer is at least measuring the rads. Please report back with your edr and perhaps some pics of your neart boiler piping and a typical radiator. Also, before commting to any one installer, please post pics of some of their work. Folks here will be able to tell in an instant if they know what they're doing. I'd be glad to share any further info about my install through a pm as I have an larger system as well.
Colleen

KC_Jones

It would also be very good to identify what type of system you have. Is it one pipe (one pipe hooked to each radiator) or 2 pipe? If 2 pipe take pictures of anything with a name on it as that will help determine they type of 2 pipe and you will get much better input. The EDR is very important and if you need any help with it post back and someone can usually offer assistance. You are doing the right thing coming here first, we are used to people coming here after they get screwed so it's nice to be able to help people ahead of time. I agree with everything vaporvac posted especially the part about pictures of the contractors steam installs, make sure you are clear with them in that you want residential steam installation pictures. If they don't want to supply them I think I would dismiss them just for that. Have you bought any of Dan's books yet? If not I highly recommend them, great education for sure!

winter_is_coming

Thanks for the help! It's rare to find a community of people who are so willing to share quality information without judging new less-informed people. I'm glad that I found you guys! I just purchased The Lost Art of Steam Heating--hopefully I can get through it soon.

My system is a 2 pipe that dates back to the 1920s. I'll take a lot of photos during my EDR fact-finding mission tonight and report my results. I can't tell you how much I appreciate your help.

KC_Jones

winter_is_coming said:

It's rare to find a community of people who are so willing to share quality information without judging new less-informed people.

A lot of us were that person at some point and we are happy to share what we have learned over time. There is a nice mixture of experienced homeowners as well as extremely knowledgeable pros on this site. Steam is a real passion and we want to help preserve these systems I think that is the big reason the information flows so freely. I have said it before this is by far the best forum I have ever been on. Welcome and we will be anxiously awaiting the pictures. Also I would suggest posting pics of the current boiler and it's piping to give an evaluation of what you currently have.

Fred

I'm glad to hear that one of the potential installers will at least do an EDR survey. That's a good first start. There is a very good possibility that you may not need a boiler as large as the one that is there now. So many boilers are well ove-sized because the installer didn't bother with the Radiator/EDR Survey. It would also be good if we could see pictures of the piping above the boiler to determine if it was properly installed, On the rare chance it was, much of that piping/header may be reusable. Whatever boiler you go with, make sure it is matched as closely as possible to the Radiator EDR, That the installer, at a minimum, installes it per the pictures in the installation/owners manual, make sure he uses both riser tappings out of the boiler and if at all possible have him install a drop header.
When you have your radiator/EDR calculations done, post those as well as the boiler that the installer proposes. Is this a Natural gas or oil burner?
I know you have only lived there for a couple years and that someone charged you to put that boiler back together but that corrosion occurred over a period that probably goes back well before they put it back together. I wouldn't use those people again, for sure. In reality, that leak is probably why the boiler was in pieces to begin with. Someone may have thought they could put a new block in it. If I'm seeing correctly, I think I see a 1994 date on that boiler plate, in the lower right corner. If the boiler is 21 years old, that seems to be an average life for most boilers.

winter_is_coming

Thanks for the input! My husband and I have been hard at work on EDR calculations and on taking photos of our system. I tried to organize the photos in a logical way--the boiler photos are first and the different types of radiators follow. I am also uploading a draft of our in-progress EDR calculation spreadsheet. A couple of notes:

1) Please let us know if you see anything wrong with our radiator classifications. We are really new at this.

2) We can't identify one of our major radiator types. An example is in photos 5a - 5d. It was explained to us that they were designed to sit under the surface of the floor to hide the radiators from view in the main entertaining spaces. Any ideas of how to do an EDR calc on these? Or what they even are? I couldn't find any identifying information on them and they are largely obscured by large duct work boxes, which makes it difficult to see anything.

3) Now that we have the total square feet of radiation per radiator section (assuming we do--ha!), what do we do now? Multiply by 240 BTU/hr, or do we need to modify that number based on our geographical location?

Oh, and @Fred -- we have a natural gas powered system.

Thanks again!

Fred

I would post the picture of those floor rads in a new post titled "Can you help identify these Steam Rads and their EDR". Someone will know exactly what they are and advise you. Once you get that info and add it to your Radiator EDR spreadsheet, you will have the total EDR requirement for your new boiler. I would let your installer do is own survey before showing him yours, just to see if they match up. If not, you can reconcile the two. When you agree on the radiator EDR total, a boiler should be selected that very closely matches that total. All new radiators have a rating plate on them that shows the Sq. Ft. of steam. That is what you want to match to. That number on the boiler does not include a 33% pic-up/piping factor that is also built into the boiler output to handle heating all the piping, the header and potentially recovery from a 2 or 3 degree thermostat set-back, if you use set-backs. No need to convert the Radiator EDR to BTU's when using the Sq. Ft. steam rating on the boiler.

Dave0176

The boiler looks like it's leaking from the short draw rod between the two split blocks. It's probably a rubber seal. Other members have said the Weil EGH boilers kinda sag in the middle because they use rubber seals instead push nipples, and there us no other support.

KC_Jones

I am going to tag @Steamhead on this one. He is usually like an encyclopedia on steam.

KC_Jones

Do I see PVC pipe hooked up to the boiler? Yikes! Also those welded joints on the header piping are not a good idea, as near as I can tell there is absolutely no swing joint there since it's all welded solid. Perhaps a pro could comment on that one, but I thought that was a no no. I would also question whether that condensate tank is actually needed or not, given the amount of height you have there it wouldn't surprise me if it wasn't actually needed and added by someone without a clue. Perhaps another possibility was not enough water content in the boiler, but there are other simpler ways to do that. In fact Weil Mclain actually outlines one method in their I&O manual for that boiler.

JUGHNE

The first company that reassembled the boiler, if they knew steam and the fact that this set unused for some time, they would have flooded the boiler then and waited for a leak to show. But maybe the seal would not leak unless it was hot.

Your city has an outdoor design temp of 10 degrees, (the coldest temp we worry about for heat needs). You have heating degrees days of about 4440 HDD. You have a 400,000 BTUH input boiler. What is your EDR, I can't open that file. And how big is your house?

In northern NE I have a -4 degree design day, with 7075 HDD.
I have a 100 year old church, over 6000 sq ft, 50'plus ceiling, all masonry brick walls, minimal ceiling insulation, original windows (of course). We have a 525,000 BTUH input boiler with 1218 EDR connected. This one pipe system will heat the building to 70 degrees when it is -10 outside, this is with winds of 25 to 30 MPH. (not wind chill factor, but an air infiltration factor not included in any design methods I've seen).

One thing you have that I don't have is indirect radiators. These typically use cold outside air coming in thru an outdoor grill and pass over the radiator via the ducting. If the air inlet is blocked you will not have the air flow to deliver the heat. Dan has stories about this in his books. When your house was built in 1920 everyone was concerned about the 1918 Flu Pandemic and thought more fresh air would protect them. So you need to burn a lot of gas to heat outside cold air. You may have an oversized boiler and also oversized connected radiation. Maybe more than needed in your balmy climate.

Do you see the "Dunham" name on more valves or other items in the basement? That will ring bells for some on this site.

JUGHNE

The PVC piping seemed to be the overflow for the feed pump tank and also the LWCO blow down drain. From the looks of the induced bend on the PVC that overflow/vent has been passing some steam or excess water?? Maybe it is a condensate return pump that has passed a lot of steam, (trap issues?) The PVC pipe would have moved the annoying steam leaking to a floor drain, may have condensed on it's way and was just hot water at the drain. I think there is a feeder control in the other boiler picture. Is that a "Ham" above the right side of the boiler?

winter_is_coming

@JUGHNE -- I think that you're onto something! The mystery radiators do not have cold air intakes, but they do have intake vents inside the house, almost like they were trying to circulate the air. This is the case in the dining room, foyer and two in the living room. The previous homeowner attached a blower fan in the duct work to attempt to circulate air in a forced air fashion (we have since removed the fan). I'm attaching photos above and below (the radiator is on the left and the intake is on the right in both photos). And you're right, Dunham is in several places on our system.

I'm sorry you can't open the EDR spreadsheet. It isn't complete yet because we don't know how to calculate the mystery radiator measurements. If we assume that each mystery radiator is equal to 100, our EDR ends up around 1200 - 1400 (we're missing at least three radiators that will need to be added over time, so there is some guesswork for final numbers). Our house is 5400 sq ft above ground and 1800 below (three floors plus a basement). We have 10' ceilings on all but the third floor, which has 8' ceilings.

@KC_Jones -- you're right about the PVC pipe. We're pretty sure that it was added by the previous homeowner and it isn't right. It is only a drain line, so it wasn't high on our list of priorities to fix (our house is a real fixer upper and it can be pretty demanding at times). We should probably address that in the new installation, so thanks for pointing it out!

JUGHNE

Maybe your indirects use inside air and recirculate the room air. If there were outside inlets they would be obvious inside the basement, closed up wall holes etc.

The book you have describes the Dunham system.

winter_is_coming

@JUGHNE -- I'm glad to hear that info about the Dunham system is in the book that I ordered. I'm waiting to get the book in the mail, so I will read it as soon as it comes in. Thanks!

vaporvac

Check out pp. 3, 5,7 (under Mepco traps) and 9 in the heating museum on this site: https://heatinghelp.com/heating-museum/category/old-steam

There are numerous article on Dunham. Your system is bound to get some attention here as it seems relatively intact and has a couple of unusual rads. I think @Dave in QCA has a Dunham system so maybe he'll pipe in.
P.s. Welcome to the world of steam! I have a feeling you'll be hooked in no time.

BobC

To get a ballpark on the in floor radiators you need to figure out the total area of the heating element. Try measuring the circumference of the heating "tubes" and multiplying that by the total length of all the tubes (add 20% length or so to account for the fins), it looks like there are at least 2 levels of tubes and don't forget the area of the end caps that tie all of them together.

This should get you close to the EDR of these.

Bob

Sailah

Hi Sandy,

If you can get me a good make/model/closeup pic or any identifying marks on the steam traps on your radiator, I can at least help with that aspect of your repair.

Peter

ChrisJ

Ah,
Although that one is a little close, happiness, is without a doubt, a good hot radiator by the john in the morning.

I never knew how true this was until I had steam heat.

Sailah

haha, never thought about it that way.

winter_is_coming

@Sailah - I am attaching two pictures of the traps. The first photo is the trap that your arrow is pointing to in the photo above. It's kind of hard to see/read because it is covered with black rubber (it just occurred to me that it might be a cap of some sort). I initially thought that it had to be a newer replacement because it is made of rubber, but when I accidentally took a black and white photo of it, I saw that there are letters on the top. I'm also attaching a photo of a different bathroom radiator trap that isn't rubber. They both say Dunham. Thanks!

Sailah

Hi sandy,

There are a couple versions of that no 1 Dunham and our cage unit would depend on some measurements. When I get in the office tomorrow I will figure out what you need. I don't know how long it's been since they have been replaced, or if they are functional or not. Our cage units need replacement covers so if you did renew them you would lose those beautiful Dunham covers unfortunately.

As an alternative, You could send them to me and I could test them, sometimes you get a good one and it lasts a century.

Dave0176

winter_is_coming said:

@Sailah - I am attaching two pictures of the traps. The first photo is the trap that your arrow is pointing to in the photo above. It's kind of hard to see/read because it is covered with black rubber (it just occurred to me that it might be a cap of some sort). I initially thought that it had to be a newer replacement because it is made of rubber, but when I accidentally took a black and white photo of it, I saw that there are letters on the top. I'm also attaching a photo of a different bathroom radiator trap that isn't rubber. They both say Dunham. Thanks!

You could use factory parts as Mepco owns Dunham Bush. I'm going to assume you'd need a 1E kit.

As for the Barnes & Jones kit I do believe the 1950 cover and cage unit will work. My only issues with the Barnes & Jones kits are they use a cover gasket, and I've seen waaaaay too many leak over the years.

winter_is_coming

It has been an exciting day! In all, we met with three very competent boiler people: a rep from the boiler supply company who will be selling us/the contractor the boiler, a consultant who is very knowledgeable about steam heat but who no longer messes with installations, and the person who will likely be doing the actual installation. The boiler supply company person did an EDR calculation and we should be getting that in the next day or two. We completed our own EDR calc (thanks @BobC for helping with the indirect radiator calcs) and came up with 1201 sq. ft. (attached). We're still not quite sure what to do with this number. It looks like it puts us completely out of the Weil-McLain EGH series and into the LGB series--I'm not sure how significant that is (or if it is even right). I'll report back with what the rep recommends when he finishes his calcs. Today, my questions are:

1) All of the boiler techs noted that the big steam feed that pipes out of our header is in the wrong place. It's in the middle. Our header is tilted, so there was some discussion of whether you could put the feed on either end, or on just one end. They said that either way, it should be on an end to ensure that the steam is dry (if it is located in the middle, the steam will be wet). It's going to be a big project to move it, but the manufacturer is going to require it to be on the end to warranty the system. Is this true? Any thoughts?

2) There are some very conflicting opinions about the large tank that is sitting beside our boiler. The return lines that go into it do not follow gravity. In fact, the piping goes up from our return lines about 2-3 feet, over a couple of feet, then back down into the tank (see the attached photos). One installer thought that the tank should be gravity fed, and that the tank is functionally useless in its current placement because it is above the lowest level of the return lines (but he thinks that we need a tank, just not in this location). The other thought that water is being pumped into the tank (you can see the pump(s?) in the photo) so the elevation of the tank isn't an issue. They all agreed that it is not vacuum operated. All of them were scratching their heads about why our house has such a large tank.

Thanks again for all of the help that you have provided so far. It has been invaluable to giving us peace of mind that we're going to figure this out.

Dave0176

At this size of a system I'd be definitly looking at a Weil McLain 480 series power burner boiler. The LGB is just a large atmospheric boiler.
http://www.weil-mclain.com/en/assets/pdf/80_lit.pdf


Or what would be the best option IMO would be to run two Weil McLain EG65 steam boilers into a 6" header and modulate both boilers on two stage gas valves set up for lead and lag. That gives a gross EDR of 1308, but with modulation. Just a thought.

KC_Jones

If the condensate is gravity returning all the way to that point behind the boiler (I'm betting it does) then I can't imagine any reason for a pump at all. It's entirely possible the water is backing up into your return pipes as high as that pipe and that's how it's getting into the tank. I am not an expert on this, but that's what I see. Perhaps one of the pros could chime in on this. Most of them on here agree it's relatively rare to actually need a tank. It's quite possible some clueless knucklehead added it years ago not knowing what they were doing. Another possibility is the old boiler was a monster that was very tall with a high water content and when the new boiler was installed with a lower water line and lower content they thought they needed the tank and some way to correct for the lower water line. Without a time machine who really knows?! Another thing it's really hard to believe you have a boiler that size connected to that much radiation and it was heating the building. That is a HUGE differential between what you have and what you are proposing. You want to be very sure of those calculations because if you oversize it too much it will cost you for many years to come. As far as the main takeoff they are sort of right. It should not be between the boiler risers no matter what. It can't just be "at and end" it must be on the same end as the equalizer. If you are getting a bigger or different boiler it will probably make more sense to just get a new header considering all the issues that one has.

vaporvac

KC_Jones said:

Most of them on here agree it's relatively rare to actually need a tank. It's quite possible some clueless knucklehead added it years ago not knowing what they were doing.
Even with my large system and a single mains, I still havent' felt the need for a condensate tank.
Another thing it's really hard to believe you have a boiler that size connected to that much radiation and it was heating the building. That is a HUGE differential between what you have and what you are proposing.
I noticed she included some garage rads etc in her calcs. Perhaps the prior owners never used them so didn't include them in the edr.
If you are getting a bigger or different boiler it will probably make more sense to just get a new header considering all the issues that one has.

I think it will be hard to keep it.
I agree with @Dave0176 , don't fiddle around with an atmospheric boiler. Get a wet-based boiler with a gas conversion burner and save yourself some serious coin down the road. That's a lot of fuel to burn and even in Ky heat is heat.
Take a look at my threads for my recent install. I have more edr than you and put in a twinned system...it's amazing how efficiently it runs, especially in the swing seasons. I'm only about an hour north of you so only slightly colder clime. You have one chance to do it right and the boilers are about the same price. Pm me if you want more details. Any reason you only want a WM? Could you post pics of this company's installs?

KC_Jones

Out of curiosity did you double check your EDR calculations on those indirect rads against the rating of what the pipe feeding it is? This is per a suggestion from Steamhead on the other thread. Just asking as a double check. All pipe sizes have a max rating for how much EDR they can support. Don't have Dan's book handy, but there are charts in there for this.

nicholas bonham-carter

Good point KC on comparing the inlet pipe size to the radiator EDR calculation.
I might also bring up Dave, boilerpro's writings on sizing a good 2-pipe system to the building heat-loss. With twin boilers, or a 2-stage gas valve, the burner can modulate down, once the pipes have been filled with steam.
This system will likely operate well on just a couple of ounces, or even sub atmospherically.
The existing header could be modified to act as a drop header, lowered to boiler top height, and connected with 2x 90's with nipples of 18-24 inch length, all screwed together. I know many here are leary of welded piping, but if it is well supported from the ceiling, and isolated from the risers by screw joints, it should be ok. The header looks to be of adequate size.
I doubt that any condensate tank will be needed.--NBC

Sailah

Dave0176 said:

winter_is_coming said:

@Sailah - I am attaching two pictures of the traps. The first photo is the trap that your arrow is pointing to in the photo above. It's kind of hard to see/read because it is covered with black rubber (it just occurred to me that it might be a cap of some sort). I initially thought that it had to be a newer replacement because it is made of rubber, but when I accidentally took a black and white photo of it, I saw that there are letters on the top. I'm also attaching a photo of a different bathroom radiator trap that isn't rubber. They both say Dunham. Thanks!

You could use factory parts as Mepco owns Dunham Bush. I'm going to assume you'd need a 1E kit.

As for the Barnes & Jones kit I do believe the 1950 cover and cage unit will work. My only issues with the Barnes & Jones kits are they use a cover gasket, and I've seen waaaaay too many leak over the years.

Just a few points...we manufacture all the cage units for Mepco here at Barnes and Jones, the difference between ours and theirs is simply cosmetic. Same is true for Trane and Armstrong.

Regarding covers and leaks. I would say 95% of the repairs we sell for thermostatic traps are sold without a cover because it's not needed. We always recommend metal-to-metal seal without a gasket. And never pipe dope on the threads, just a tiny bit of copper anti-seize.

When a repair requires a cover due to the height difference, again we always prefer metal-to-metal. Our covers are machined on Mori Seiki CNC lathes here in MA that are still holding +/- 0.0003" tolerance. Whether the 100 year old mating casting is still holding tolerance or free of nicks, is out of our control. In the instance where the installer is getting a leak, or we have heard repeated trouble with a bad sealing surface on a particular trap, we will supply a cover with a gasket to help with sealing.

KC_Jones

If you don't have the charts for the pipe size capacities just post the size feeding each one and what you calculated as the EDR and we can compare the figures for you.

Fred

To your question about where the risers out of the boiler should go. Both risers out of the boiler should be carried over to one end of the header and be situated next to each other (the end opposite the equalizer). This will eliminate any the issue of steam colliding in the header if it were coming from both ends of the header and meeting in the middle. After the risers, your Mains should tie into your header and then the equalizer should come off of the header on the other end. The header should have a slight pitch towards the equalizer to allow any water in the header to return to the boiler. I too doubt that you need that tank. Gravity should do all the work.

vaporvac

Here's a little video that illustrates what @Fred just wrote:
https://heatinghelp.com/systems-help-center/near-boiler-piping-video/
P.s. I'm curious if your consultant is local to Louisville?

Bio

Your mistery radiator can be found on page 122 and up
https://archive.org/stream/idealfitterradia00amerrich#page/122/mode/2up
Found it on a different thread
http://forum.heatinghelp.com/discussion/155834/help-identify-edr-of-trane-steam-convector#latest

winter_is_coming

Thanks @Bio for helping with the EDR on our indirect rads. Unfortunately, the EDR calculations went up...a lot. The total is now 1550 (please see the updated calculation spreadsheet). The pipes feeding each indirect radiator are 3/4" in diameter (does this sound right @KC_Jones? It seems small to me, but I don't have any charts to reference). We're still waiting for the boiler supply person to send us his complete calculations and boiler recommendations. I'll update when I have something.

And @vaporvac, I asked the supply person for his opinion on a twin system and he wasn't a big advocate. Right now, we're probably looking at a single boiler system. I like the idea of a twin system (your system is a beautiful thing), but given the limited professional technical help we seem to have in our area and the short time parameters we are forced to work with, I'm just not sure that it would be wise for us to design anything other than a basic system. And to answer one of your earlier questions, we're not married to a Weil-McLain system--it's just all that we know and it seems to check out as one of the better boilers out there. That, or we have some weird Stockholm syndrome with the brand, since the one that we had crapped out on us two years after having it rebuilt. Ha.

KC_Jones

I am not the best with the pipe capacity charts, but if those indirects are being fed with a 3/4" pipe there is no way they are rating at 120 and definitely not at 156. The highest rating for 3/4" pipe is 56 EDR for gravity return on a 2 pipe system. Something doesn't seem right. Perhaps a pro with a bit more experience can offer some insight here. With numbers that high I can't help but comment that house must be enormous.

Dave0176

winter_is_coming said:

Thanks @Bio for helping with the EDR on our indirect rads. Unfortunately, the EDR calculations went up...a lot. The total is now 1550 (please see the updated calculation spreadsheet). The pipes feeding each indirect radiator are 3/4" in diameter (does this sound right @KC_Jones? It seems small to me, but I don't have any charts to reference). We're still waiting for the boiler supply person to send us his complete calculations and boiler recommendations. I'll update when I have something.

And @vaporvac, I asked the supply person for his opinion on a twin system and he wasn't a big advocate. Right now, we're probably looking at a single boiler system. I like the idea of a twin system (your system is a beautiful thing), but given the limited professional technical help we seem to have in our area and the short time parameters we are forced to work with, I'm just not sure that it would be wise for us to design anything other than a basic system. And to answer one of your earlier questions, we're not married to a Weil-McLain system--it's just all that we know and it seems to check out as one of the better boilers out there. That, or we have some weird Stockholm syndrome with the brand, since the one that we had crapped out on us two years after having it rebuilt. Ha.

Winter-is-coming

With an EDR that large in a single family home I think your best bet is to go with a two boiler system. I'm a Weil McLain man so I'd spec out two EGH85 boilers, or two Weil McLain 380 power burner boilers. The power burners will run quite a bit more and I'm not so sure about modulation. With the two EGH85s you can run them on two stage gas valves with one boiler being set a bit higher as the lead boiler. The reason behind all this is because you won't always need that much heat. That is a design day temp that you size to, so on warmer days the boilers will modulate.

winter_is_coming

Thanks, @KC_Jones. I agree, 3/4" does seem small. But the piping appears to be original/very old and the measurements of the sections are exactly what are in the manual that @Bio referenced. We weren't able to get super exact measurements because these things are in huge boxes and they're difficult to see, but I feel like at least the general calcs are correct.

And you're right--the house is a monster. It's a 1920s center hall colonial with approx 7200 sq ft of total space (three stories plus a basement). That being said, @vaporvac seems to have a similar space and she has a slightly lower EDR (assuming that our indirect radiator calcs aren't way off). I don't know if my house has radiator overkill or what. I have learned a lot from you guys, but I'm still really new to this. The good news is that my The Lost Art of Steam Heating book came in the mail today, so I'm studying up!

KC_Jones

I guess what I am saying is with a 3/4" pipe it doesn't matter what you are measuring the pipe is limiting the output to a max of 56. So even if you hook up a radiator the size of the titanic the pipe limits the output. This is why I am hoping a pro with more experience will chime in. Even though I am posting it, it doesn't make sense to me. Oh and since you have the book, flip to page 129 and you will see the chart I am talking about. What size is the return pipe? It should be even smaller...just want to make sure you are looking at the correct pipe. lol

winter_is_coming

@KC_Jones --I totally see what you're saying. We just re-measured and the pipes going in and out are the same sizes. They measure 4.25" in circumference. When we compared that to the diameter for a schedule 40 pipe, it equals a diameter of 1" per pipe. So, it looks like we have 1" pipes feeding in and out on the indirect radiators, which is slightly larger than what I previously said. I'm sorry for the confusion. It still doesn't look quite large enough to support the EDR that I'm getting, but it's at least in the right ballpark.