steel vs. cast iron oil boiler opinions?

[bwsaw]

We have an energy efficient (by 1987 standards) 2,000 sq ft contemporary in NH with 2 zone baseboard hot water heat and tankless hot water coil. Our Burnham V-714T cast iron oil fired boiler is on its last legs (internal leaks), and our trusted oil supplier/HVAC installer has recommended either a steel New Yorker boiler or a more efficient cast iron Weil-McLain for 20% more.
We're told the steel boilers are now as durable as cast iron, if not quite as efficient.

1. Opinions on steel vs. cast iron, considering the price differential?

I also asked about a load calc, and was told that we would be getting the smallest boiler made for the application (90,000 BTU's if I remember right), and if a load calc recommended something smaller there was not much we could do if we wanted to stay with the current oil and baseboard hot water set-up.

2. Does this sound like reasonable advice?

Thanks for any help and advice you may have, all I know so far is what I've skimmed off these forums in the past day.

[beenthere]

A steel boiler should last about as long as your V7 did.

Hard to find an oil boiler that fires at less then .65 gallons per hour(91,000BTUs input).

I would think about getting an indirect water heater though.
That will still use the boiler to make your hot water. But, won't require the boiler to maintain a high temp in the summer.

[2nu2no]

Most of the New Yorker boilers I see are older then 23 years, but I work for a Weil-McLain dealer the WTGO is a nice boiler.

http://www.weil-mclain.com/en/our-products/boilers/oil-fired-boiler/wtgo-oil-boiler.aspx

[bwsaw]

Thanks for the quick reply, and a few follow-up questions if you have time:

A steel boiler should last about as long as your V7 did.

I assumed the V7 would last longer than this. Will the new cast iron boiler be any more durable (serviced annually of course)?

Hard to find an oil boiler that fires at less then .65 gallons per hour(91,000BTUs input).
The current V7 says .95 gph, does this mean it was considerably oversized?

I would think about getting an indirect water heater though.
That will still use the boiler to make your hot water. But, won't require the boiler to maintain a high temp in the summer.
I'm not sure that's an option because of the space, a 4.5 x 6.5 utility room on a slab.


Thanks again for your comments.

[beenthere]

Well. The V7 is known to have some problems.

Steel will last a long time. If it doesn't have to be opened. And fresh water added to often.

Weather your old boiler is over sized or not. I can't tell from here. But a .95 nozzle is around 133,000 BTUs input.

Yeah. An indirect does take some space.


You can do your own load calc. HVAC Calc (http://hvaccomputer.com/talkref.asp). Its worth its 49 dollar fee.

[inhoth2o]

Weil McLain are good boilers but a lot i think you pay for the name, there are a lot of good quality efficient cast iron boilers out there now, the new yorker steel boiler comes with a tankless coil, but do go with an indirect water heater with either boiler and check out having an outdoor reset installed, new yorker now has cast iron boilers made by burnham

[beenthere]

new yorker now has cast iron boilers made by burnham

New Yorker is owned by Burnham holdings(Burnham boiler).

[bwsaw]

do go with an indirect water heater

no room for an indirect, see above

[2nu2no]

The WTGO has a domestic coil, no need for indirect tank. I post the hyperlink in my first comment.

[subcooler-65]

It's worth it to install an Indirect even if you have to put it in another room nearby. Mate it with a cast iron 3-pass boiler like a Biasi B-10. I wouldn't install a tankless boiler unless you absolutely have too.. Looking back at your original post, the boiler/indirect would fit no-problem....Do a Google search on Biasi.

[HydroAirJoe]

The WTGO has a domestic coil, no need for indirect tank. I post the hyperlink in my first comment.

Yeah but to make these system work in the real world, you need to mate it with a storage tank (aquaboost). If you are going thru the bother of a storage tank, which requires a circulator, you might as well install an indirect with its own zone and add neat features like DHW priority.

[bwsaw]

Yeah but to make these system work in the real world, you need to mate it with a storage tank (aquaboost). If you are going thru the bother of a storage tank, which requires a circulator, you might as well install an indirect with its own zone and add neat features like DHW priority.

I understand a tankless coil is not the most efficient set-up. Our old coil provided an ample supply of hot water, and time/space/$$$ constraints mean that is what we'll stick with for now.

[da_poppa]

Have you considered the Energy Kinetics System 2000? www.system2000. It's a high quality, high efficiency steel boiler made in the USA.

Steel boilers got a bad name 50 years ago in part due to the so-called "contractor boilers". They were cheaply made and a lot lighter to move around in new construction than the cast iron boilers available at the time so were very popular. For the most part they were dry base and only mediocre efficiency. The warranty was generally 10 years and a lot of them lasted about that long.

There were a few very high quality, high efficiency steel boilers made even before that, among them the GE low pressure and the Bethlehem Dynatherm. GE stopped marketing them in the late 60's and Dynatherm is still in production. There are a lot of the early ones still in use after 40 or 50 years. It's not the material it's made of that counts, it's the design and quality of manufacture.