a few questions about oversized oil steam boilers

zathrus

First post here. I have endeavored to search a lot so as not to repeat. Thank you in advance to this site for being such a great source of info.

I have a Burnham v73 made in 1998 (in my house from the early 1930s) which has had a hole in the top of the block for a couple years (it was a small hole when I moved in and is now a larger uglier hole). It still heats the house, thank god, but it blows steam out the chimney and wastes god knows how much money.

I have calculated my radiators' EDR to be 183. (I'm reasonably certain that I'm right about that but will double check it all later.) The plate on my current boiler says its net IBR is 379 sq ft.

1) Am I right in thinking this is pretty severely oversized?

2) Do boilers fail early BECAUSE they are oversized? Or is it only a performance concern?

3) I haven't had any short cycling or severe banging noises, just a bit of hissing at the rads and some sounds of metal heating up, and some boiling noise from the boiler and agitation in the glass, but I don't really know what consitutes proper boiler sounds/behaviors. Should things be calmer than that?

I know I will end up with many more questions. I really appreciate any and all responses.

Jamie Hall

Double check your EDR -- but if you are anything close to right, you current boiler is about twice as big as it needs to be.. so when you get a new one, get one rated for your EDR!

An oversize boiler won't necessarily fail any faster than a properly sized one -- that one has given you good service, and they don't last forever.

You don't have short cycling because any excess steam which the poor old thing produces just goes out the chimney. Not helpful...

You can expect some small bouncing of the water in the sight glass when the boiler is operating -- opinions differ, but a total of an inch or an inch and a half up and down is quite normal, in my opinion. Metal heating up -- expansion noises -- is also normal, but can be minimized by making sure the metal is free to expand. Can take some detective work to find the tight spots.

zathrus

Yes, I suspected I might not have symptoms because of the freedom the steam has to go out the chimney. Sadly I have no comparative idea how the boiler behaved prior to it being broken. I will double check my EDR.

Robert O'Brien

That's pretty much the smallest oil fired steam boiler.

zathrus

I don't know if my posting of these pics will be successful but I took a picture of every radiator and here are my calcs for each according to one of the many EDR charts out there:

3-column rad with height 38" x 3 sections = (5 x 3) = 15
2-column rad with height 38" x 6 sections = (4 x 6) = 24
2-column rad with height 38" x 6 sections = (4 x 6) = 24
5-TUBE rad with height 23" x 12 sections = (3 x 12) = 36
2-column rad with height 38" x 13 sections = (4 x 13) = 52
2-column rad with height 38" x 8 sections = (8 x 4) = 32

15 + 24 + 24 + 36 + 52 + 32 = 183

Am I wrong?








Also for completeness here is a pic of my current boiler's plate:

Fred

I think your EDR calculation is correct. Look for a boiler that matches that EDR as closely as possible.

Steamhead

Staying with oil or switching to gas?

JUGHNE

Any wet returns that you can not see...under the floor.....or any steam piping not visible?
Fresh water added over time can cause leaks.

Your problem is compounded by losing steam out the chimney in that you must be adding water.

How about some pictures of the piping around the boiler showing pipes floor to ceiling.

HVACNUT

Look at the Burnham Mega Steam. At 288 sq ft it's about 25K larger than you need but I dont think you'll find much smaller. The Peerless ECT-3 is a bit lower but IMO an inferior design compared to a 3 pass.
Of course check all from ^^^.
And get yourself a qualified steam pro.

Robert O'Brien

Megasteam is the ne plus ultra of oil fired steam boilers

mikeg2015

Isn’t the megasteam with a Riello gas burner the setup that can reach 85% on natural gas? Low approach flue temps I’d guess around 225F, 2% excess air to hit that number. Good stuff.

Robert O'Brien

No US Boiler oil boiler is approved with a gas burner. And I wouldn't want to be in a house with a burner running at 2% excess air or even 20%

HVACNUT

I think only roaches can survive 2% excess air.

zathrus

Staying with oil. And I have been told by multiple people that Burnham's are no longer a quality unit, but of course there are 20 opinions available on every unit, so I guess it's all a roll of the dice? I have one guy who has offered to put in a New Yorker, which I know is owned by Burnham, but are they perhaps of different manufacturing specs? The CL3-091S has a net AHRI of 233 sq ft according to their product specs here https://file.ac/miVehSSt4ks/CL I&O.pdf

Here are a few pics of the current piping:

Robert O'Brien

That's the same basic HX you have now but down fired. Need a chimney liner

zathrus

Does down fired mean the only thing different is the burner and not the block or other large components?

Regarding a liner, that corrugated metal sticking out of the chimney is a stainless liner... it looks just like the one we had put in at my parents' house for the wood stove, so I assume it goes all the way up, although I must admit I haven't actually looked.

mikeg2015

Sorry, not sure where I came up with that number. Was probably thinking 2% O2.

HVACNUT

> @mikeg2015 said:
> Isn’t the megasteam with a Riello gas burner the setup that can reach 85% on natural gas? Low approach flue temps I’d guess around 225F, 2% excess air to hit that number. Good stuff.

Sorry, just having fun. Most modern residential oil burners want 4.5-6.5% O2, 25-30% excess air. All other gases should meet their parameters within those settings with correct draft and 0 smoke.

ethicalpaul

zathrus said:

Staying with oil. And I have been told by multiple people that Burnham's are no longer a quality unit, but of course there are 20 opinions available on every unit, so I guess it's all a roll of the dice?

Definitely have a look at the mega steam, if I was stuck with oil I'm sure that's what I would get.

Jamie Hall

In answer to the down fired question -- yes, many times that is the case. In fact, most boilers will have a range of firing rates over which they will give good combustion and efficiency.

As to review opinions... um. Well, if these are internet available opinions, I would treat them with a great deal of skepticism. Remember that in general the folks who are annoyed are the ones most likely to post their problems.

zathrus

Interesting. On viewing the manuals available for the New Yorker steam boilers, it seems that every version of the CL3 (the CL3-091S, CL3-105S, and CL3-140S) all share the same block and many other parts. So is the main difference between these the nozzle that comes with the burner?

HVACNUT

> @zathrus said:
> Interesting. On viewing the manuals available for the New Yorker steam boilers, it seems that every version of the CL3 (the CL3-091S, CL3-105S, and CL3-140S) all share the same block and many other parts. So is the main difference between these the nozzle that comes with the burner?

Yes. Like @Jamie Hall wrote above, a lot of manufacturers have different firing rates for the same boiler. As in your NY numbers, input can be between 91K and 140K. Some will only meet Energy Star standards with a particular nozzle, and or burner.
Anyway, about that MegaSteam...