Wicked old two pipe, no traps

GW

Hi all- any danger signs? Slide in a new one and set up a vapor stat? Check valves stay? Don’t want to get into a can of worms. Boiler is working but homeowner wants to modernize 
thanks 

Jamie Hall

That boiler is remarkably like the one that preceded Cedric, @GW . My only comment... well, two. Make sure the check valves are free, and make sure the new water line matches the old one.

Try the vapourstat at 3 ounces cutin/7 ounces cutout.

Then sit in that delightful rocking chair for a while...

ethicalpaul

For the love of all that is holy, save that beautiful gauge!!

JUGHNE

First picture looks like a scary ski mask.

I see a lot of concrete blocks in your future as that is a pretty high water line.

GW

YES! that old gauge will not be scrapped. Jamie yes that's great advice. I measured all the rads, and didn't do the long hand yet, but the gas is flowing 225k. I'd build a fat riser and drop the manifold to grab those two 2" mains. Gotta get the asbestos guy over there. When I blurted (she asked) the rough price range on the sweet lady, she says "I thought my friends were kidding me when they said take the price of what you paid for the home and divide it by two" (she bought this house a very long time ago).

ChrisJ

Jamie Hall said:

That boiler is remarkably like the one that preceded Cedric, @GW . My only comment... well, two. Make sure the check valves are free, and make sure the new water line matches the old one.

Try the vapourstat at 3 ounces cutin/7 ounces cutout.

Then sit in that delightful rocking chair for a while...

What is the reasoning for the water line to have to match? Perhaps this setup wouldn't mind if it dropped?

I'm asking because I feel if Gary understands what's going on, he'll have a chance to assess and then determine if he can move the water line rather than just stacking the boiler 2 feet up in the air for no reason.

The man has a back and it's best we don't abuse it for no reason.

Isn't there also a way to create a false waterline?

ethicalpaul

Oh and you better go one size larger on that boiler just to be sure 😂

GW

Chris, thank you for that, stacking blocks is a piece of cake. We’re messing with an old vapor system, it’s probably best to slip the new boiler, tricking the old system to believe nothing ever happened!

Jamie Hall

GW said:

Chris, thank you for that, stacking blocks is a piece of cake. We’re messing with an old vapor system, it’s probably best to slip the new boiler, tricking the old system to believe nothing ever happened!

Exactly.

JUGHNE

I was looking at the wet returns. In the rocking chair picture it looks like both EOM's drop there well below the water line.

How does the air get out of the steam mains?
Does it all have to pass thru the rads into the dry returns?

I should look at the book....

Is that a "Taco" pressure relief valve....that would be a collector museum item IMO.

EBEBRATT-Ed

Those old Smith 24s lasted forever

EBEBRATT-Ed

@JUGHNE I think the old Taco was an indirect water heater for DHW. Hence the two pipe connections like a double flow fitting. Looks like an old coal bin. Must have been coal to oil to gas or maybe just coal to gas.

The wet returns are pretty low probably don't have to raise the new boiler much. I would think there would be a big air vent up or around the Moline alternating receiver.

JUGHNE

Thanks ED, I see the Taco now in another picture and it looks like a real "side arm" of the boiler.

Don't see a relief valve anywhere, could be hiding in the insulation.

EBEBRATT-Ed

@JUGHNE

Probably on top of the header which we can't see. That is where Smith usually put them

Steamhead

@GW et al- two words: "Moline Heat"!

This can be found in chapter 15 of @DanHolohan 's "Lost Art". Read that and you can't go wrong.

I will say that if that were my house, I'd get rid of the atmospheric burner and put in a Carlin power burner. Those Mills boilers were some of the best.

Jamie Hall

JUGHNE said:

I was looking at the wet returns. In the rocking chair picture it looks like both EOM's drop there well below the water line.

How does the air get out of the steam mains?
Does it all have to pass thru the rads into the dry returns?

I should look at the book....

Is that a "Taco" pressure relief valve....that would be a collector museum item IMO.

Yes -- that's how many vapour systems worked. All the air goes either through crossover traps or the radiators and into the dry returns, and thence out through whatever main venting was used. Works like a charm.

GW

@Steamhead will do, my first Moline. 

Do you think the boiler will last forever? I’m not dying to yank the old system, just trying to keep an elderly lady from stressing out if the system ever takes a turn into the weeds. The powerpile died a few weeks ago and we politely told her that anything more significant could be trouble, and she took our words to heart (and her friends and relatives concur)

I could slide a new burner in- if this was your aunt or mom what would you do? I don’t think the nice lady will go to the poor house on this project. This seems to be her second home, she’s been in Europe since the beginning of the great pandemic 

Gary 

Ironman

I’d recommend that you remove the vacuum valve (the large shower head) from the line off of the air trap and install a couple of Gorton #2’s or Big Mouths.

Here’s a Moline that we just did:

http://HeatingHelp.com

GW

ethicalpaul said:

Oh and you better go one size larger on that boiler just to be sure 😂

Gonna downsize this bad boy to about 177k if we pull the trigger 
1st fl rads are somewhat cropped out, all the math is there though 

Steamhead

Some more Moline stuff:

https://forum.heatinghelp.com/discussion/182196/found-a-moline-heat-system-near-baltimore

GW

Ironman said:

I’d recommend that you remove the vacuum valve (the large shower head) from the line off of the air trap and install a couple of Gorton #2’s or Big Mouths.

Here’s a Moline that we just did:

http://HeatingHelp.com

Bob that link isn’t working, can you paste the link again? 

Ironman

@GW

Let’s see if this works:

https://forum.heatinghelp.com/discussion/comment/1780111#Comment_1780111

Steamhead

GW said:

@Steamhead will do, my first Moline. 

Do you think the boiler will last forever? I’m not dying to yank the old system, just trying to keep an elderly lady from stressing out if the system ever takes a turn into the weeds. The powerpile died a few weeks ago and we politely told her that anything more significant could be trouble, and she took our words to heart (and her friends and relatives concur)

I could slide a new burner in- if this was your aunt or mom what would you do? I don’t think the nice lady will go to the poor house on this project. This seems to be her second home, she’s been in Europe since the beginning of the great pandemic 

Gary 

Hard to tell. If she's willing and can afford the removal labor and asbestos abatement...........

EBEBRATT-Ed

At the age of that boiler, it is impossible to predict when and if it will fail. I guess when you present her with the #s you will have a better guess at what to do.

I guess the options are:

1. new burner and controls
2. new boiler--remove old
3. new boiler --leave old in place

Looks like there might be enough room to leave the old one in place. But some would consider it a hack job.

That boiler was made with a minimum of 5 section to a maximum of 10. To me I am guessing about 5 section from the pictures. The 5 section will do 500sq ft of steam so it pretty well matches what you came up with.

I guess if you/she thinks she will be in that house for a while then do it all and get it over with. However, chances are if the boiler has been they're this long it will last another 5 years, probably more.

Alan (California Radiant) Forbes

Boiler is working but homeowner wants to modernize

How long do you think it would take to pay off a new boiler. Me? I'd leave the beautiful beast alone.

Mad Dog_2

Leave it...Some Gorton #2s.  The Pressuretrol may work fine.  Snowman boiler...aka Sherman Tank...Mad Dog 

Sylvain

Nice feature:
The sight glass and LWCO are not directly connected to the boiler but via a large diameter pipe.
That helps avoiding deposit in those two parts.
I have seen this on an old system here in Europe 45 years ago.

clammy

As stated chk your water line and match worse comes to worse build a false water line ,either disassemble and clean or replace all check valves and run a vapor stat and discount edr by 20 % . I Would update any crossover traps and replace any main air vents w Hoffmann 67 vapor vents if she still pulls into a vacuume . I would remove the bull headed tee also even though it’s been there for decades I think I would be issues being that old boiler produced better quality steam due to it design and steam chest size then a modern even w a drop header .
Peace and good luck clammy

GW

Thanks all, once the asbestos guy gets in there, I’ll send her the final numbers 

vtfarmer

I can't resist jumping in: a house with an almost 100% original heating system which is in good condition is SO COOL (er, hot I guess). Were I home shopping in that market I would pay a premium for a house with that kind of setup (though I know I'm in the 0.01% who would, lol).

I would then swap the atmospheric gas conversion burner for a low speed flame retention oil burner, but that's just me (the 0.0001%, AKA just @Jamie Hall and me). I do like the plaid paint job on the current burner, though.

mattmia2

clammy said:

and discount edr by 20 % .

I was thinking about this a lot. The vapor system is designed to not completely fill the radiators with steam(so it all condenses before it gets to the return) and the piping for 2 pipe is smaller than 1 pipe because it doesn't need to deal with both steam and all of the condensate so the 30% pickup factor baked in to the boiler EDR rating is likely also significantly bigger than the actual pickup factor.

Will the system evenly distribute the steam even if there isn't enough to completely fill the system? Could you factor both of these in and size the boiler to say 80% with a 10% pickup factor(using the btu output rating of the boiler, not the EDR with the 30% pickup factor added in) and have the vaporstat never have to do any work and evenly heat the house?

This is definitely put your hands in your pockets and think and research before you do anything.

ethicalpaul

the 30% (or 33% I see sometimes) is massively oversized even for 1-pipe.

ChrisJ

My vote is 63-04L

His radiation is 452sqft.

mattmia2

ethicalpaul said:

the 30% (or 33% I see sometimes) is massively oversized even for 1-pipe.

I din't say it wasn't, but it is even worse for 2 pipe plus you add the metering for the vapor system and if you do it by the ratings plate edr you're probably around 50% oversized.

GW

ChrisJ said:

My vote is 63-04L

His radiation is 452sqft.

I always thought 30% was on the higher side, and 15-20 was good when all the pipes were insulated (they are). These rads are absolutely gigantic. So that makes sense---steam likely doesn't reach the end of the super large rads

Jamie Hall

Ah yes. The how big is too big problem. Keep it small! Don't allow 30%, keep it less! I always got and still get -- mightily entertained when the folks in the nice clean shirts and pants and the slide rules or the calculators turn up on a job. The fact of the matter is that you can crunch the numbers on paper or in bits of silicon all you want, but the question is, does it work? Is it going to heat the house the way you want it to heat on a cold day? And every single application is going to be different. What works in one situation will be oversize in another -- or just plain not big enough in the one just down the street.

The only application on which I have really truly solid numbers is my own Cedric. Cedric powers a system with a nominal EDR 0f 1,250 square feet. If I run through the numbers on fuel input and efficiency for him, he has a nominal power output of 380,000 BTUh. That EDR has a nominal capacity to absorb and meke useful warmth of almost exacly 300,000 BTUh. That makes Cedric 30% oversize, based on those numbers.

How does this work out in practice? Well, after about 50 minutes of run time, from when the burner starts cold, he will shut off on pressure (6 ounces per square inch). He will then cycle on roughly a 1 minute off 7 minute on basis until the thermostat is happy (all this assumes coming out of the morning 2 degree setback). That equates to an average power output from him of about 315,000 BTUh. By number crunching logic, he could be downfired to be only 5% oversized and still be "right", and being a big Weil-McClain, in fact he could be if the right size nozzle could be found (the right size being halfway between one size and the next one up -- good luck with that). But what would the heating performance be? The radiation which he powers is quite well matched to the various rooms -- and being "exactly" the right size would mean that he would never quite be able to fully heat the biggest or slowest radiators.

Is this desirable? Not in my house it's not.

Bottom line -- my view is to give yourself some wiggle room when selecting a boiler. Make sure that at full rated power it really is big enough -- and I doubt that that nominal 30% is far off, once when starts looking at the tolerances in the numbers (the EDR, for example, could just as easily be 10% low as "right on") and then plan, if it turns out that the unit really is too big as installed, try the next smaller nozzle... if the unit can be downfired at all.

Just my take.

It puts me in mind, perversely, of a car I owned many many moons ago -- a 1955 VW convertible. Flat out on level ground it could go faster than any speed limit in the US (it was also a lot of fun). It also took forever to get there. Upgrade on the Massachusetts Turnpike? I was outrun by every Peterbuilt on the highway. That little fourbanger was "adequate" -- nominally. Was it in real life? Um... not so much.

ChrisJ

@Jamie Hall He's looking at atmospheric gas boilers.
There will be no smaller nozzle.


30% is too big.
That's why hot water switched to 15%.


In GW's case, the building heatloss sounds like it's closer to 60K.

mattmia2

Here is the original moline brochure:
https://heatinghelp.com/assets/documents/27.pdf

The Steam Whisperer

IIRC, boilers for Molines should be sized to only 80% of the radiation. That's what the radiator orifices are sized for. If the system doesn't have the original adjustable orifice valves, then I'd orifice it to the current heating needs. This would allow you to downsize the boiler to the current heating load ( and not the radiation load). Read all the Moline info you can get.
Lowering the water line should help you, as you get more b-dimension... everything returns back into the water level. Keep in mind that there are 3 pipes on this system, supply, return and condensor pipe coming out of the Moline ( venturi) fitting up on the ceiling. The length on this condensor pipe is in the literature....about 35 feet IIRC. This condensor line, along with the Moline fitting, create a vacuum on the return to give incredible distribution. The condensor line is sized to prevent steam from reaching the end of the pipe at the proper maximum operating pressure (8oz). DO NOT INSULATE THIS PIPE AND USE AN OUNCES VAPORTSTAT. The saucer shaped device is a very sensitive check valve to allow the system to go into vacuum. It has a diaphargm on some type ( I haven't ever pulled one apart) which is probably shot and should be replaced with a teflon ball check valve with no spring ( apollo makes them).

ChrisJ

The Steam Whisperer said:

IIRC, boilers for Molines should be sized to only 80% of the radiation. That's what the radiator orifices are sized for. If the system doesn't have the original adjustable orifice valves, then I'd orifice it to the current heating needs. This would allow you to downsize the boiler to the current heating load ( and not the radiation load). Read all the Moline info you can get. Lowering the water line should help you, as you get more b-dimension... everything returns back into the water level. Keep in mind that there are 3 pipes on this system, supply, return and condensor pipe coming out of the Moline ( venturi) fitting up on the ceiling. The length on this condensor pipe is in the literature....about 35 feet IIRC. This condensor line, along with the Moline fitting, create a vacuum on the return to give incredible distribution. The condensor line is sized to prevent steam from reaching the end of the pipe at the proper maximum operating pressure (8oz). DO NOT INSULATE THIS PIPE AND USE AN OUNCES VAPORTSTAT. The saucer shaped device is a very sensitive check valve to allow the system to go into vacuum. It has a diaphargm on some type ( I haven't ever pulled one apart) which is probably shot and should be replaced with a teflon ball check valve with no spring ( apollo makes them).

So a 63-03 in this case? Or the L?

Voyager

Jamie, the car analogy doesn’t hold though unless you have a car where the engine can be only off or full throttle. There are some old French airplanes that were made this way. They had no throttle and were controlled by turning the ignition on and off. I saw one fly at Old Rhinebeck Aerodrome and it was a challenge to fly.

Cars have throttles and the engine can thus operate at a nearly infinite range of power outputs from near zero to their max HP. I don’t think many steam boilers have this capability. Hot water boilers do better now with multi-stage burners, but still lack the fully analog throttle of a car engine.

Yes, driving an underpowered car is a pain and I owned two 1970s era Beetles and am well familiar with that, but this isn’t a good analogy. A better analogy would be to a car that has only two throttle positions, idle and full. In that case, a 40 HP Beetle would be a lot more fun to drive in most situations than say a 400 HP muscle car. The Beetle engine could be left at full throttle when on the open highway and only need to occasionally be cut to idle when going downhill or when in a town or to maintain a speed slower than top speed, which was 81 MPH in my Beetles if memory serves. The 400 HP muscle car would require constant cycling between full throttle (and smoking tires) and idle to maintain any speed less than 150 MPH (sound familiar to anyone with a grossly oversized boiler?). And driving such a car in the city would be an absolute nightmare.

I will argue this is a more correct analogy between cars and boilers. Now if boilers had an analog throttle like car engines have…