Looking for the correctly sized steam boiler?

gkijowskio

Help please!

The block on our Columbia boiler (24”x28” footprint) cracked after 24 years. It’s been heating our house effectively with no repairs (serviced annually). The Burnham replacement (24”x42” footprint) looks to be 50% larger than the Columbia and seems like it would be appropriate for a house twice the size of ours.

Concerned the unit is over-sized which might require that it be throttled back, excessive cycling, more oil consumption, more noise, 8” flue required rather than 7”, etc..

KC_Jones

They have to measure all the radiators, come up with a EDR of the system and then pick the boiler with that rating.

The rating on the old was 710, in the Burnham series you have there is one rated at 787 which would have been closer than the 833 they are giving you, but as I said what is there is irellevent they need to add up radiation and calculate boiler size.

How did they size it? You don't even know if the original was correct. I'm guessing a big house 4000 sq ft+

I'd be very skeptical what you have is correct based on what you posted. We could help you figure out the EDR, so you know what you should be getting.

http://www.weil-mclain.com/sites/default/files/field-file/boiler-replacement-guide.pdf

Start on page 9 in the above link and you can calculate the EDR, don't add anything extra don't convert to BTU's just calculate the square footage of all the rads.

gkijowskio

House is 1,800 sq ft - 2nd and 3rd floor with 750 sq ft walk-out basement (kitchen and family room).

KC_Jones

I would be using that chart and measuring all the radiators at this point. I have a feeling you are grossly oversized. To be clear the square foot measurement refers to how much radiation, not the size of the house.

KC_Jones

If you need any help adding up the radiation let us know, we are glad to help.

Fred

Wow, that's a big boiler. My Burnham is about that same (866 SF) size and is too big for my 5000 SF house with 15 Radiators that total 700 EDR. Measure your EDR, I'm guessing that is at least twice the boiler you need.

gkijowskio

Thank you for the comments and with the kind offer of help I could come up with the EDR.

However, is there a simple way to directly compare the two boilers, based on the nameplate information, as to whether the Burnham is 50 to 100% larger than the Columbia - regardless of the required heating for the house? (Again, having the 24 winters of experience with the size/capacity of the Columbia working great for our house.)

Are there any inherent issues with using the higher capacity Burnham from an operational perspective moving forward?

Is there a way to clearly make the case to the contractor they’re putting in the wrong sized unit?

Danny Scully

@gkijowskio, you have to measure all the radiators, period, stop

And yes, there are a number of issues associated with an oversized boiler.

KC_Jones

Add up the EDR, that is a clear fact as to what your system is and factually proves what is and isn't correct.

The calculations aren't difficult. IMHO having 24 years with the old one is anecdotal. You could have 30 with the new and think everything is just fine, but is it running its most efficient? You could could go to a smaller boiler, perhaps a much smaller boiler and not only have a good running system, but a more efficient system. This saves money, also saves you money up front on the install.

Also why pay someone to not do their job? In the time it took me to type this we could have probably lu calculates the EDR of your system.

EBEBRATT-Ed

@gkijowskio,
It will take you all of an hour to measure the radiators and then you will know the correct size.

You came here looking for help because the new boiler is obviously the wrong size.

@Danny Scully, @Fred & @KC_Jones gave you the correct advise. What you do with it is your choice.

Your original boiler is probably way oversized

Fred

@gkijowskio said:
Help please!

The block on our Columbia boiler (24”x28” footprint) cracked after 24 years. It’s been heating our house effectively with no repairs (serviced annually). The Burnham replacement (24”x42” footprint) looks to be 50% larger than the Columbia and seems like it would be appropriate for a house twice the size of ours.

Concerned the unit is over-sized which might require that it be throttled back, excessive cycling, more oil consumption, more noise, 8” flue required rather than 7”, etc..

@gkijowskio , reread your original post. You came here knowing this boiler is likely a problem. We are just advising you that it probably is and I doubt you can thro back enough to size it for your needs and even if you could, why buy and pay for a boiler larger than you need? Do as everyone has advised; calculate your radiator EDR. That is your way to clearly make your case to the installer. That and letting him know your aren't paying for that thing until he makes it right.

neilc

I don't see that that header pipe is correct either,
where is the equalizer?
or is that unfinished work(I hope?)?
post finished near boiler piping also

Fred

neilc said:

I don't see that that header pipe is correct either,
where is the equalizer?
or is that unfinished work(I hope?)?
post finished near boiler piping also

I also saw that the rear riser out of the boiler doesn't seem to have a Tee in the header to tie it in either but I have to assume all those things are still a work in progress. Maybe the plan is to run it over to the Tee just past that union but it seems to me that tying it in where that coupling is (right in front of the boiler riser) would have made more sense) Sizing the boiler correctly is the first step to a proper installation. The whole project makes me nervous.

gkijowskio

Thank you for making the issue clear about the necessary
calculations.

The system is not finished.

Based on my calculations (if correct) is the unit the “wrong” size for our house? Don’t know how to determine the BTU capacity for Burnham Model V8H8S?

KC_Jones

The constant is avtually 240 per sq ft of EDR, but like I said you don't have a need for that. The total EDR is 598. You size the new boiler based on that. The old one was rated 710 (over sized ~19%) the new one is rated 833 (oversized ~40%).

They need to take that thing out of your basement and bring in the proper sized boiler. Also your calcs for the basement aren't correct. You have to do a manual J heat loss calculation of the space to find out how many BTU's are required, also that baseboard isn't even capable of emitting the amount you calculated so it's impossible.

That being said, a hot water zone off a steam boiler works within the pickup factor and unless the zone is ridiculously huge (yours is not) you don't even factor it in.

I would not let them continue work at all on this job, you can go down 2 boiler sizes in that model line. No way would they be getting a single penny from me until they made this right...on their dime. Their lack of doing math isn't your fault and shouldn't cost you. You are about to find out how good or bad of a company you decided to do business with.

This contractor is a joke, can't even be bothered to do those basic calculations. Sorry, but we see this all the time on here and it's shear laziness....and you are now paying for their laziness. Me, I don't pay people for that.

AMservices

EDR=598
EDR x 240 = 143,520 BTU'S (radiator output)
If the steam supply piping is uninsulated then its recommended adding a pickup factor of 33% to that number because the bare metal will act as a radiator, condensing steam.
143,520 x 1.33 = 190,881 BTU output
The BTU input is what the burner fires to give you the 191K your system needs.
So if the boiler is 85% efficient, to get 191k output you need 225k input.

The old boiler had a maximum input of 2 gallons per hour (280,000 BTU input)
Heating capacity was 226,800 BTU'S ÷ 240 gives square feet of steam 945.
The 170,300 steam btu hour is hiding the pickup factor.

The new boiler has a maximum input of 2.35 GPH
(329,000 BTU'S)

Those are maximum firing rates. Not what it can be fired at.

gkijowskio

Guys, I so appreciate all the input each of you provided on my original post!

The contractor is removing the Burnham V8H8 tomorrow morning and installing a Burnham Mega Steam MST629.

Again thank you, this wouldn’t have happened without your expert help!

KC_Jones

That's wonderful! That is a much better more efficient boiler also. Honestly shocked they didn't start with that model.

Any explanation for using the wrong size in the first place?

Fred

Fantastic! I'm glad this worked out for you. Now stay on top of him and make sure he pipes it correctly.

JUGHNE

Did anyone notice what appears to be the date code on first new boiler? Is it 03/2017 ? if so that has been sitting somewhere for awhile. Nothing wrong there but often it is a discount in a supply house to get something moving before more warranty runs out the clock.

Now your new Megasteam will come with a lengthy book which includes piping diagrams (the minimum requirements).
You should study that......it is your property.
Or print out your own pages of piping diagrams.
Any questions could be directed here.

gkijowskio

The answer about boiler size had to do with availability?

Looks like the install manual for this model is not online? Does anyone know where I might find one?

Fred

gkijowskio said:

The answer about boiler size had to do with availability?



Looks like the install manual for this model is not online? Does anyone know where I might find one?

If the right size is available now, that's a much better wait than going twenty years with an over sized boiler and waiting for it to die so you can get the right size in there.

Manual is the same for the MST513
https://www.manualslib.com/manual/23100/Burnham-Megasteam-Mst513.html?page=12#manual

KC_Jones

> @gkijowskio said:
> The answer about boiler size had to do with availability?
>
> Looks like the install manual for this model is not online? Does anyone know where I might find one?
>
>
>

That makes no sense to me, is love to hear a contractor comment on putting in improper equipment due to availability.

it sounds like a line to me, but you are on track now and that's all that matters.