Looking into New Boiler - What to consider (besides EDR)?

a3inverter

Greetings all,

Given the age of our gas-fired steam boiler (we suspect it's 50 years old or so based on some research), some attractive rebates and loan offers from our local utility, and other factors, we are starting to investigate a replacement. It's working fine now and always has in the 3 years we've been here, but...it's really old.

When we bought this house (west of Boston) a few years back, I performed an EDR calc based on Dan's books and what I've read on this site and I get to 179k BTU. Our current boiler is rated for 185k BTUs for output so I think the size is appropriate and would aim to get the same size.

Given that this will be a significant investment, I certainly want to 1) pick the right boiler 2) pick the right installer and 3) do everything I can to make it last a long time. I have read stories on this forum about boilers lasting 8-10 years. As compared to the old beast in my basement, that's awful.

I will certainly avoid the automatic water feeder and do regular blow downs, as well as annual inspections.

Are there brands/technologies to avoid? When I have looked into furnaces in the past (our old house had gas-fired forced hot air) it seemed that the things added to make them more efficient just reduced the MTBF (mean time between failures). I have experienced the same for fancier, quieter, more efficient appliances. Does the same hold true for modern steam boilers? Are there features that are worth the investment?

Given the size, it doesn't appear that I have a lot of choices in terms of a residential unit - and efficiency looks to be between 82 and 84 percent.

Your thoughts are welcome.

Thanks!

Bob Bona_4

Contractors have thier favorites, and I think it comes down to what's easily available. IMO, and I've installed Peerless, Weil Mc, Utica, Burnham- I'd lean toward push nipple construction. The control and gas trains are pretty standard across the board. A 20-25 year life cycle reasonable.

I don't have to elaborate on how critical the near boiler piping is!

ChrisJ

Can you post some pictures of the old beast?
If it's a 3 pass boiler and in good shape I'd highly consider keeping it. If it's a snowman I'd ditch it.

If you get the new boiler really clean and run water treatment you should have no issues with the block rotting on the new boiler. It won't go 50 years but may go 30 if treated right.

SWEI

Also -- no need bother converting to BTU's for sizing on a new boiler -- just square feet of EDR (with a possible de-rate of a few percent depending on your piping, insulation, etc.)

a3inverter

Hatterasguy said:

"It's really old" is not a criterion for replacement. The cast iron of 50 years ago my possibly last longer than the next boiler that you procure. It's not in the interest of the manufacturers to have boilers with such longevity and they have done everything possible to further their interests in that regard.

Have a competent professional check out the boiler and determine the condition of the heat exchanger and overall deterioration of the cast iron. The only danger with this approach is that most of them are self-serving and won't give an honest opinion. If they comment, "This is really old"..............just get rid of them.

JA is well respected and will give you the straight dope on whether it needs to go or not:

https://heatinghelp.com/find-a-contractor/detail/j-a-phinney-plumbing-and-heating

I completely agree with you on the "really old" perspective, however, mission control here at the house is of a different opinion. And I fully expect that any new boiler is unlikely to last as long. But each year that goes by, the larger the odds that this one bites the dust, perhaps at the most inopportune time.

I will give JA a call. Thanks.

a3inverter

Bob Bona said:

Contractors have thier favorites, and I think it comes down to what's easily available. IMO, and I've installed Peerless, Weil Mc, Utica, Burnham- I'd lean toward push nipple construction. The control and gas trains are pretty standard across the board. A 20-25 year life cycle reasonable.



I don't have to elaborate on how critical the near boiler piping is!

Nope, fully onboard with the criticality of NBP.

a3inverter

ChrisJ said:

Can you post some pictures of the old beast?
If it's a 3 pass boiler and in good shape I'd highly consider keeping it. If it's a snowman I'd ditch it.

If you get the new boiler really clean and run water treatment you should have no issues with the block rotting on the new boiler. It won't go 50 years but may go 30 if treated right.

Pics attached. The rusting under the drain on the right side was due to a rusty nipple, replaced last year and no longer leaking. The soot up the front, must be from the past as well as I've never seen it shoot flames out the front.

ChrisJ

a3inverter said:

ChrisJ said:

Can you post some pictures of the old beast?
If it's a 3 pass boiler and in good shape I'd highly consider keeping it. If it's a snowman I'd ditch it.

If you get the new boiler really clean and run water treatment you should have no issues with the block rotting on the new boiler. It won't go 50 years but may go 30 if treated right.

Pics attached. The rusting under the drain on the right side was due to a rusty nipple, replaced last year and no longer leaking. The soot up the front, must be from the past as well as I've never seen it shoot flames out the front.

I'd call JA.

vaporvac

Also be sure the water lines are the same to avoid having wet lines now becoming dry. What is the actual EDR of your system?

When I inquired the same here a few years ago, it was recommended that I go with a wet-based boiler with a gas conversion burner. I did and haven't regretted that choice. They are much smaller with a smaller steam chest, but are more efficient for a number of other reasons, as well. That said it is not new or fiddly technology.... just borrowed from oil boilers. They use a probe LWCO so no blow-down and depending on size can use a two-stage burner. They are heavier, but if you're not putting it in yourself that shouldn't matter. Their NBP is even more important so I'd encourage a drop-header, a combustion analysis is mandatory to set up the burner, as is a double-swing barometric draft, but that should come with the boiler. You'll need to ensure it has a spillswitch for the dsbdraft. They're no more expensive to buy, install or maintain....probably easier.
Here are links to my posts on the subject: http://forum.heatinghelp.com/discussion/142753/best-practices-for-install#latest

a3inverter

My EDR is 748...

a3inverter

a3inverter said:

My EDR is 748...

It was suggested to me (on the basis of prior posts I made regarding my combo one-pipe and two-pipe system) that mine may have been a vapor system. It's a combo today because all the first floor rads were converted to one-pipe (at some point in the 85 year history of the house - patched holes opposite the supply side of each rad reveal the secret) and none of the present day two-pipe rads have shut-off values (but the elbows, at least from the outside look a lot like the return side orifice pictured on page 112 of Greening Steam.

Steamhead

a3inverter said:

a3inverter said:

My EDR is 748...

It was suggested to me (on the basis of prior posts I made regarding my combo one-pipe and two-pipe system) that mine may have been a vapor system. It's a combo today because all the first floor rads were converted to one-pipe (at some point in the 85 year history of the house - patched holes opposite the supply side of each rad reveal the secret) and none of the present day two-pipe rads have shut-off values (but the elbows, at least from the outside look a lot like the return side orifice pictured on page 112 of Greening Steam.

Post some radiator pics please!

a3inverter

Second Floor Hallway Rad - Two Pipe - Supply Side

Second Floor Hallway Rad - Two Pipe - Return Side

First Floor Lav - One Pipe

JUGHNE

FWIW: From the pictures of your boiler it appears that the only wet return piping is all right at the boiler. I just throw this out for any other homeowners that might be in your situation following this thread. With a boiler change out the wet returns, if any, should be cleaned, inspected and possibly replaced.

There have been postings here describing a new boiler install and the wet returns, which were part of the problem, were never looked at. Anyone considering change out should bear this in mind and ask the prospective contractor his opinion of this. To come back and do this later would be a considerable upcharge. If done with the change out it might be more reasonable. IMHO

Fred

With that kind of EDR, if/when you replace that boiler, you definitely want to use two risers out of the new boiler, into a drop header. I think just about any of the major brand boilers, Burnham, WM, Peerless are probably equal in terms of longevity. Burnham and Peerless have the brass push nipples between each section. WM uses a rubber/composite material but that seems to serve them well too. Just looking at that boiler, I too think it would be a good idea to have ja look it over (the burner and flue as well).

PMJ

I am currently running a Bryant of the same vintage - 1950's. Bigger than yours (465,000 input) and on a 2 pipe system. Fabulous boiler. I won't part with it until absolutely necessary and will take my chances it might be at an unfortunate time. The water is always totally clear and the system doesn't use any water. I keep feed water valve off and check it every day. Never drain it or add any chemicals to the water. I keep the standing pilot on all summer. Clearly it is very happy just like it is.

Frankly I couldn't bear to replace it with something it might outlast - even at its already advanced age.

Steamhead

That definitely looks like a hot-water system converted to steam.

a3inverter

@PMJ - I know how you feel. My maintenance approach is much the same as yours.

Overall, there doesn't seem to be a lot of interest in the part of my local plumbers to get involved in replacing it. I think the "hybrid" nature of the piping and the potential callbacks has them looking elsewhere.