How old is my boiler? Options for replacement?

wildrage

This frigid cold weather has made me think about how terrible it would be if my boiler failed. I've had 2 different heating guys look at it, and they've told me that it was a solid unit and could 'last 100 years', and not to worry about it (sigh). I guess I tend to worry too much. I moved into the house 2 years ago, and am unsure of the age. My guess would be 80's or 90's based on the installation docs that I have with it.

It's a Weils-McClain EGH-85 series 2 @ 280,000 BTU output. It looks like they are still making the model, but are up to series 5. I believe this is considered a commercial unit.

Does anyone know when the Wiels-Mclain came out withe the series 2? or how often they release a series? They have a website to look up serial numbers, but it doesn't apply to the EGH series boilers.

Assuming that its 30 or so years old, would it be wise to replace it in the off season? If so, it doesn't seem like there are many options at the BTU rating. Was thinking the path to least resistance would be going with another EGH-85 series 5...assuming I really need that many BTUs and proper sizing calculations have been made (of course). They are in the $7-8k range.

I've been burned by being 'proactive' and replacing aging things with new things, only to find that the new ones work worse, or fail shortly...so I'm a bit torn. It's currently working pretty damn well, and I hate to mess up a good thing!

Gilmorrie

30 years, if that is the age, isn't very old. My boiler is 65 years old, and runs like a champ, although it has been maintained and updated.

But, the first step would be to perform a heat-loss calculation to determine the correct size. 280,000 Btu is enormous for most residences, so you sure don't want to automatically install a replacement boiler of the same size. But, I would relax if I were you, and go with what the two experts have told you.

wildrage

@Gilmorrie Agreed. So believe it or not, I also have a forced air furnace thats 180k BTUs for the 1st floor, that replaced the old gravity fed steam system, which puts me at 460k. I did a quick and messy calculation and that seemed within range...but of course I would do it more scientifically. Victorian 3 story approximately 6000 sq ft and 13 foot ceilings, 1500sqft basement. Double stormers and lots of attempts at insulation, but still pretty drafty. Both units running on natural gas.

nicholas bonham-carter

If the forced air was installed after the steam boiler was first installed, and the radiators removed, then it may now be oversized.
Does the system use much makeup water?
Pictures of the boiler and piping would enable us to see how well the boiler was piped, and therefore make educated guesses about its longevity.—NBC

wildrage

@nicholas bonham-carter I can go take some pictures. I've been told that the header is a bit low, only about a foot to 1.5, but has been functioning well. Very little make up water needed. Takes about 7 mins for first radiator to get hot, and about 25 to get them all hot. About 30 mins for a typical call for heat. In this crazy weather, been running about 1 30 min cycle every 0.75-1.5 hours.

Both systems seem of similar age. The forced air is Westinghouse which I don't beleive exists anymore, so shows its age . it's actually kind of nice, because on mild winter days, the forced air doesn't need to run at all. On average winter days, it runs a few hours.

I'm pretty certain that the ductwork and the vents are original to the house. I've been told they are from an old gravity fed steam system...and I'm not really sure what that means. The Vents (10) are in common areas and in bedrooms. Radiators (15) are in stairwells, bathrooms, kitchens, and maids quarters on the 3rd floor.

Jamie Hall

It was not at all unusual to have a gravity hot air systems in houses such as yours. The steam system may actually be newer than the ductwork, but the hot air furnace is probably newer still.

As to replacing the boiler, if it ain't broke, don't fix it. That's not old enough to be horribly inefficient (now if it were from the '20s...), provided it's set up correctly, with proper measurements, and maintained -- and any increase in efficiency would take quite a while to pay back the cost. You'll get the most bang for your buck by keeping after the draughts and by ensuring that the steam system is adequately vented to run on rather low pressure.

Fred

@wildrage , my boiler is 35 years old and I have no intentions of replacing it until it leaks. If that happens in the dead of winter, oh well. Like you, I have forced air furnaces that will provide back up, if needed. There is really no need to dump a perfectly working boiler for a new one until the old one dies.
One other point, one a steam boiler replacement, you want to calculate the total connected radiator EDR, not do a heat loss. The boiler must be able to supply the connected radiators, no bigger than the Sq. Ft. of steam rating on the boiler plate and not much smaller or you run into a whole different set of issues.

mikeg2015

Most boilers by the 80s were 80% effecient with intermittent ignition. I have 1983 HB Smith about the same size.

I doubt you actually need that much heating. Bet it only needs 200-250k at design conditions. Maybe less. 3800sqft here and 90k is all I need. Similar construction.

Heck, you can take the average temp on the gas bill and apply it to useage and make a pretty descent calculation.

wildrage

@Fred @Jamie Hall

Thanks, guys...I think I just needed a lot of confidence.

That's one thing I've learned from living in a 110 year old Victorian house. If it ain't broke, don't fix it....it can open a biiig can of worms.

@Jamie Hall Do you know where I can find more information about gravity fed hot air? I have this ductwork in the most random places, but only some of them are hooked up to the hot air furnace. From what it looks like, wherever the "rich" people in the house were, it was ductwork. Wherever the "staff" was, or in bathrooms, it was steam. No rooms have both ductwork and steam, so I wouldn't be surprised if it was planned that way. Its kind of nice in the master bed, becasue it has ductwork, but also 2 attached rooms (nursery and bathroom) with steam, so I get double the heat.

2 Furnaces is slightly annoying, but hey, I'm a fan of redundancy as well. Beleive it or not, I have a 3rd furnace that was installed about 5 years ago and barely used. It's a Keystoker Coal forced-air furnace that's also tied into the ductwork via a cutover switch...I haven't dared to try that one out yet though. I live in coal country, so it's not bad to have a backup.

The house also has about 15 electric baseboard heaters in drafty areas. They are ugly, but come in handy sometimes, especially on nights like this.

KC_Jones

wildrage said:

They have a website to look up serial numbers, but it doesn't apply to the EGH series boilers.

That's weird, they must have removed the information. In 2014 when my boiler went south I put the serial number into their website and it gave me the date back. I wonder why they would remove the data?

Did you try it or just read that the info wasn't available? I'd try anyway just to see.

wildrage

@mikeg2015 You are probably right. Right now it is zero degrees out with 40 MPH winds. The boiler is coming on every hour or so for 30 mins at a time. I had read that at design conditions, the boiler should be basically running all the time, right? I'm pretty damn close to design conditions for PA right now.

wildrage

KC_Jones said:

wildrage said:

They have a website to look up serial numbers, but it doesn't apply to the EGH series boilers.

That's weird, they must have removed the information. In 2014 when my boiler went south I put the serial number into their website and it gave me the date back. I wonder why they would remove the data?

Did you try it or just read that the info wasn't available? I'd try anyway just to see.

It literally says on the site "This doesn't work for EGH series boilers"...weird, right? I couldn't find anything on my boiler other than the model and series number - so maybe some just didnt' have a serial number? I was hoping to atleast find a copyright on installation documents (they saved all of them - even for the low water cutoff), and I can find nothing. Based on the pictures and the text on the paperwork, my guess would be 1978-1990. The last owners bought the house in 1976, so it fits into that time line as well.

mikeg2015

... so if average temp for a month was 25f and you used 1500 therms, then if design is 5f then tounare 67% duty cycle that month you would used about 2240/30days/24 hours which is about 310k btu. Assuming 80% equipment efficiency, that’s a heat loss of 389k btu. So if that was the average temp over the billing cycle and you had about a $1500 gas bill then that’s your heat loss.

Jamie Hall

Hmmm... well, off hand I don't know. We also have a gravity hot air furnace -- like you, in the rich people area! -- in the principle place we care for. Unlike, you, we have a complete history -- and the gravity hot air was in use when I first started caring for the place (it isn't now; rusted out).

The two main considerations with gravity hot air furnaces were, first, they rusted out. Usually there were cast iron bits for things like ash pit and stoker doors, but most of the rest of it was sheet steel. Heavy gauge, but not heavy enough. You don't have that problem. The other consideration, though, was getting them circulating - which could take an amazingly long time. Once they got going, though, they were totally silent -- and remarkably good at heating.

In your situation, I would carefully look at all the ductwork, and really figure out which ones were feed ducts and which ones were returns. Since you have a new (?!) installation and some of the ducting was disconnected, this may take a bit of deduction. Then, if possible, I would get all the ducts thoroughly cleaned, particularly if coal was used, and see about hooking them all back up. And sit back and enjoy!

wildrage

mikeg2015 said:

... so if average temp for a month was 25f and you used 1500 therms, then if design is 5f then tounare 67% duty cycle that month you would used about 2240/30days/24 hours which is about 310k btu. Assuming 80% equipment efficiency, that’s a heat loss of 389k btu. So if that was the average temp over the billing cycle and you had about a $1500 gas bill then that’s your heat loss.

@mikeg2015
Ok, so from Nov 15 to Dec 15 I used 471 CCF. The average daily temperature was 39. On average, the boiler was running 4.5 hours a day, and the forced air, maybe an hour or 2 a day.

Fred

@KC_Jones , he has a Commercial Weil MccLain boiler. I have a commercial Burnham. For whatever reason, most manufacturers don't make public a database for commercial grade appliances, like they do for consumer grade. They can tell you manufacturing date, if you call and are fortunate enough to talk to a person. I'm not sure why that is.

wildrage

@Jamie Hall Ok, so there is definately only 1 register in some rooms, but each register has 2 switches to open and close. Could it be a 2 in 1, or were there just no returns? Right now, the forced air furnace just sucks air from the basement.

wildrage

I know the header should be higher, but doesn't seem to causing and problems.

Jamie Hall

wildrage said:

@Jamie Hall Ok, so there is definately only 1 register in some rooms, but each register has 2 switches to open and close. Could it be a 2 in 1, or were there just no returns? Right now, the forced air furnace just sucks air from the basement.

They could be 2 in 1. Can you pop the register cover off and take a look at how the duct -- or ducts -- connect? That said, often there were only one or two big (and I do mean big -- in this place, 24 inch diameter) return ducts, and they were on the ground floor. The idea was that the hot air would rise into the upper floors particularly, with some into the ground floor, and the returns would collect it and bring it back to the furnace. There may also have been an outside air connection, with a damper, to the return plenum. May not have been, too...

GW

it's like asking your friends if you should update your car----you'll get lots of opinions. Just run it till it drops, if you like excitement.

wildrage

@Jamie Hall In the bedrooms, they are 20"x12" and appear to have 2 separate grills with independent switches. The things have been painted over 100000x and has molding around it, so don't feel like taking it apart at the moment There are no other registers in the bedrooms. There are 3 large rooms on the 1st floor - like all 3 are in the neighborhood of 40x25x13. They each have 2 of those large registers, along with a smaller one in each room - here's an example of one. I didn't take a measurement but I'd guess closer to 12"x8"....no air comes out of them, and oddly enough, I can't find any duct work in the basement going up to them. I do see ductwork for each of the large registers. Here's an example of a small one, that seeming does nothing:

Fred

Registers, with no ducts were often used in period houses in rooms that had gravity fed hot air. They allowed some heat to pass from one area to another or, in some cases, allowed cooler air to pass into rooms that had a return air duct. Might that be the case in your home? In some cases, they even used the spaces between the wall studs to act like duct work to allow cooler air to fall to the basement.

wildrage

@Fred Yes, it's a 1906 home, and the owner owned several coal mines, so it adds up. It looks like registers were left alone, while the ducts were retrofitted with forced air. It makes sense, and I don't see any other option - other than start installing steam radiators in these areas.

I still find it hard to believe that the house was designed to have 2 boilers. Maybe that wasn't uncommon? There is definitely no ductwork in room with radiators, and it doesn't appear that there were ever radiators in rooms that have ductwork.

Jamie Hall

How did you happen to acquire such an ark? I know how it happens that I'm taking care of this one, but... ?

Two boilers wasn't all that unusual for really big houses. Nor was the practice of only putting steam in where the hot air wasn't.

If you can really reconstruct the hot air system -- and figure out how returns were hooked in -- I'd be very much inclined to resurrect it. It will give you some options, such as air conditioning and very straightforward humidification and dehumidification, if you wanted to add them. However, it is very much dependent on getting the original air circulation -- particularly returns -- restored as much as possible. It's also dependent on large ducts at low velocities.

Fred

@wildrage , You have a large home. I would have to say it was not typical to install two boilers back then, but the logistics and size of the structure may have played a role in how they decided to heat the house. Are you sure the house was built all at the same time? There was a period when they even built what they called a 'Half House". The first half was asymmetrical and later they added the other "half" that completed the more symmetrical design of the house. Does there appear to be any logical divide between which sections of the house has steam and which appears to have had gravity hot air?

mikeg2015

> @wildrage said:
> ... so if average temp for a month was 25f and you used 1500 therms, then if design is 5f then tounare 67% duty cycle that month you would used about 2240/30days/24 hours which is about 310k btu. Assuming 80% equipment efficiency, that’s a heat loss of 389k btu. So if that was the average temp over the billing cycle and you had about a $1500 gas bill then that’s your heat loss.
>
> @mikeg2015
> Ok, so from Nov 15 to Dec 15 I used 471 CCF. The average daily temperature was 39. On average, the boiler was running 4.5 hours a day, and the forced air, maybe an hour or 2 a day.

39f is 45% duty cycle. That puts you at about 120,000 btu to heat the house at 5f. But that doesn’t factor in sunshine or stack effect. But I doubt you need over 150k depending on how warm you keep it.

Keep in mind even a small 60k btu furnace running continuously would use around 432 cubic ft per month.

Most homes have slightly to massively oversized equipment. Steam systems however must be sized close to the radiator output. But radiator output is modulating as you can partially warm each one up so it’s not an major issue.

Gilmorrie

wildrage said:

@mikeg2015 Right now it is zero degrees out with 40 MPH winds. The boiler is coming on every hour or so for 30 mins at a time. I had read that at design conditions, the boiler should be basically running all the time, right? I'm pretty damn close to design conditions for PA right now.

If you are close to design conditions, then, based on your info, the boiler is oversized by a factor of two.

EBEBRATT-Ed

@wildrage , yes the header is a little low but looks like it is piped correctly. The size of the steam takeoff from the header leads me to believe the boiler is oversized.

My 2cents

Do an accurate heat loss and check radiation sizes, Decide if you want to add steam radiation in areas served by the furnace and come up with the total steam load...check pipe sizes etc

Then if your old boiler quits you will have a plan in place.

I would run it until it quits, you have nothing to loose you have the furnace and electric heater to keep you out of serious trouble if it fails during cold weather

Jamie Hall

It's a bit more complicated than that, @wildrage . The idea -- with modern calculations which, of course, weren't available when our systems were designed and installed -- the idea is that the system, as a whole, will be able to just keep up at the "design" conditions.

However.

First off, the design condition is a temperature, and wind load is not considered. Nor is it the coldest temperature on record for the area. For both of these reasons a system designed to the modern approach will not keep up on some days. The dead men knew this. They also knew that folks -- particularly folks like those who built our places -- wouldn't accept a system which worked 80 to 90 percent of the time, and were willing to pay for a system which was, by modern standards, overdesigned.

Second, and perhaps more important, we are looking at a system, not just the boiler(s) or whatever, and usually in a steam heated building the limiting factor on system capacity is not the boiler, but the installed radiation, and they installed the radiation which they felt would keep up to what was needed. It is up to us moderns to take that installed radiation and match the boiler to it, as has often been pointed out in various threads.

The end result is a system which, by modern standards, is overdesigned by as much as 50% or sometimes even more -- both the radiation and the boiler. But from a comfort standpoint, is it really? A big old house, perhaps not as well insulated or draught stopped as a modern one, with perhaps four stairwells (one a grand stairway), perhaps with a wonderful view... I too am running about 60% duty cycle as I type. It's -3 and a 15 knot wind. Tomorrow night I expect -10 and a 20 knot wind. This is well beyond modern design conditions -- but I also expect that while it may be a bit chilly around the edges, Cedric will keep up.

There is a capital cost to overdesigning, no mistake. But there really isn't a running cost, so long as everything is properly matched.

wildrage

@Jamie Hall I hear you loud and clear. My guess is that the rating here in PA is 60 degrees. Right now the windchill is -17. My cycle rate has increase to about once every 40 mins. Seems to make sense, just as the radiator is starting to get luke warm to the touch, the next cycle is beginning. If I was rated at 60 degrees, theoretically, I may not make it past 50 on the thermostat. I have a ridiculous number of windows, and while I would love to just install new ones, 1) The smallest windows I have are 6 feet tall, and 2) I have some really ornate lead and stained glass ones that I'm not willing to part with.

After doing a full calculation, it would be nice if I could lower my BTUs to less than commercial grade equipment. It seems like I have a lot of options there, but we shall see. I'm a bit of a 'prepper' by nature. I almost want to buy the boiler, and have it staged in my basement for that fateful day, as crazy as that may sound.

@EBEBRATT-Ed Thanks - that's the path I was going down; its good you agree . I think I had read too many gloom and doom posts about boilers failing after 15 years and I got a bit paranoid...expecially with the weather, and doign nothing but searching for things online because its so damn cold out.

@mikeg2015 Thanks for helping me with the calculations. Seems like the high end of residential output (from what I've seen, about 180k btus) might end up working for me. As I listed above, that would be nice because it seems like there are more options. Seems like being oversized by 20% might be more realistic.

@Fred I'm fairly certain it was all built at once. Here is a post card that I have postmarked 1910 and the house looks the same....well...with some battle scars and vinyl siding lol. The house was built in 1906.

Jamie Hall

Don't replace the windows!!! Good heavens! Please! It is far more satisfactory, and no ore expensive, to carefully refurbish the ones you have, and then install properly designed storm windows. There are several different varieties of inside mounted storm windows, such as the ones this outfit makes: http://www.stormwindows.com/ which are really good. They will work perfectly with your leaded and stained glass windows.

Modern windows don't have the look or feel -- and don't last.

wildrage

@Jamie Hall You can't tell from the picture, but there are storm windows on the outside, and a set of removable ones on the inside. Still drafty, but I'll put up with them...even if I have to be ghetto and put plastic shrink wrap on the inside (which I did this year haha).

Steamhead

@wildrage , I think that ductwork was probably built for "indirect radiators", where steam heated cast-iron heat exchangers in the ductwork and the hot air rose by gravity. This was typical in high-end houses at that time. Most of them also included fresh-air inlets.

nicholas bonham-carter

Air infiltration is the enemy here, and your storm windows will probably do a better job at keeping the house relatively tight than any replacement windows-over the long term.
The interior storms are a real pain, if they have to be removed, and stored, and may contribute to the rot of the original windows. Far better to have good quality prepainted exterior combination storm windows, such as you may already have.—NBC

mikeg2015

My house was built around 1905-1907. Lots of steam options back then.

Don't replace the windows Get some good fitting, descent quality Low-E coated storm windows for about $150-250 each vs 600+. Easy DIY installation... takes longer to clean the glass than install them. Then repair and rebuild the originals when you get time and money.

1) Payback on replacement windows for energy savings is 100-250 years.
2) historic winds last indefinitely, only need glazing and cords replaced every 70-80 years. No reason they won't still be serviceable 300 years from now. Modern replacement are disposable. They cannot be rebuilt. chuck every 30-50 years and start over like a boiler.
3) Historic windows when is good condition are perfectly balanced. I have 4'x7' double hung windows that open easily despite each sash weighing probably 30lbs.
4) Zinc or copped seals work very well when everything is adjusted properly and will last 200+ years.

I have 2 replacement windows from the 1980's. Both are foggy, seal worse than my 114 year old windows and can barely be opened. They construction is no different than windows I bought in 2006 on a previous home.

A single pane window plus a Low-E storm window performs 90% as well thermally as a double panel window, and is quieter because of the larger air gap between panes and the differences in glass thickness and size (resonates at different frequencies)

Only windows I'd consider replacing are picture windows. I have 3 of them. But even there, a good storm window is more effective than replacing it, and lighter.

mikeg2015

Gilmorrie said:

wildrage said:

@mikeg2015 Right now it is zero degrees out with 40 MPH winds. The boiler is coming on every hour or so for 30 mins at a time. I had read that at design conditions, the boiler should be basically running all the time, right? I'm pretty damn close to design conditions for PA right now.

If you are close to design conditions, then, based on your info, the boiler is oversized by a factor of two.

At 0F and 40mph winds you are actually beyond design conditions in most of the US and it should be running continuously and even falling behind by maybe 1F early in the AM before sun comes up.

Here's a handy chart.

I'm around 0F where I live. Looking at tun time I'm using about 120,000BTU at that temp to keep it a comfortable 67-69F. That's about 31btu/sqft. given the same construction as mine, I guess that 185,000 at 0F would be about right. However, you should be a little lower, since outside wall area matters more than sqft of volume. Your ceilings are slightly higher but i might have more proportional window area.

Boston, MA is +12F like most of the north Atlantic region for example.

https://articles.extension.org/sites/default/files/7. Outdoor_Design_Conditions_508.pdf

mikeg2015

Here's my old postcard of my home

https://pin.it/aqdcvla5urwi6t

wildrage

@mikeg2015 That's awesome. Yea, I was able to find 2 or 3 post cards of my house. Pretty neat.

Thanks for the window information. I'm not sure what's currently on as storm windows. They appear to be sort of screwed on there. Not onto the windows themselves, but sort of into the flashing around the windows, if that makes any sense. I have about 30 sets of plexiglass inner storms as well. They have a felt-type backing to make a seal against the wall. It looks like they were probably very expensive to fabricate. I've been here almost 2 years, and I learned the hard way that they really need to come off in the spring. All my blinds got melted this past summer. Also doesn't look super healthy for the windows themselves. They are all coming off in the spring.

The kitchen was remodeled in the 90's, and Pella windows were installed. They are by far the leaky-est and crapiest windows in the house. Thankfully, there are only 4 of them.

I'm really interested in the storms you spoke about...atleast to compare them to what I already have. Thankfully, I have few windows facing West, but the 4 or 5 that do might be good ones to start with. Do you have a link online to an example?

EDIT: Oh, and I forgot. I have two flat roofs that jut out from the rear of the house. I'm sure that I lose a terrible amount of heat from them.

Thanks!

wildrage

Steamhead said:

@wildrage , I think that ductwork was probably built for "indirect radiators", where steam heated cast-iron heat exchangers in the ductwork and the hot air rose by gravity. This was typical in high-end houses at that time. Most of them also included fresh-air inlets.

I thought I remembered you telling me that. Now that I think about it, the mains run on either side of the house, right under that ductwork. I bet that if I look, I'll find capped risers, or some evidence near the ductwork, no? I guess, unless the mains were replaced over the years.

Jamie Hall

try the ones this outfit makes: http://www.stormwindows.com/ which are really good