Efficiency of new steam boiler vs. old

Zorian Pinsky

Hi,

I am considering replacement of my Weil-McLain 70+years old steam boiler, oil burning. The system is two pipes with condensate collector. I am trying to calculate how long would be the pay-back time.

How much more efficent the new boiler would be?

Thank you.

Zorian

P.S.

FYI, about fuel prices in our area, Milwaukee, WI. This coming season: oil - $1.80/gal or gas - $1.40+/term (including 5.6% sales tax and misc. charges, for gas only).

Steamhead

That would depend

on how inefficient the old boiler is.

If the boiler is round, you might cut your fuel consumption by up to 50% by replacing it. Most of these old round boilers could not reach over 40% efficiency on oil or gas, and they weren't great on coal either. A new one is going to be at least 80% efficient on an annual basis (AFUE, measured throughout the heating season including off-cycles).

If the boiler is square, its efficiency will probably be better. If the burner is a high-efficiency model and the installer placed suitable baffles in the boiler's flue passages, you might see a high-70's efficiency.

Once the boiler has generated the steam, its job is done. From that point, the system must move the heat to the radiators. This is where many steam systems can be improved. Tell us more about your system- have you located any manufacturer's info on the radiator valves, traps, etc. that would help us identify it? And what about that "condensate collector"? Taking some pics and posting them here would be a big help.

Zorian Pinsky

To do the job, I am gathering estimates from local contractors and am learning about the system from them - not too many are knowledgeble, although. The last guy (with 30 years experience) told me that my system has small condensate collecting tank. The system with new boiler (McLain is his preference) would have condensate collector, for sure, because new boilers have much smaller volume of water inside of them. The current boiler is not round.

Steamhead

Most residential steam systems

don't need condensate tanks and pumps, because even with the smaller water content in new boilers, there's usually plenty of water.

I've removed these units from some systems, and they've actually run better without them. The only place they would be needed is if you have radiators below the boiler's water line and the condensate could not return by gravity.

If you don't have a copy of Dan's book "The Lost Art of Steam Heating", you really ought to get one. It has more information than a lot of contractors do. Order your copy on the Books and More page of this site.

If you're in the Baltimore area, e-mail me!

Zorian Pinsky

condensate collector

I am taken back by your response. Both of the proposals I received mention either "feed system for make-up water, repiping return system into feed tank" or "install a new condensate pump and condensate receiver to prevent overfilling of boiler".

The boilers that are proposed are Burnham V903A or McLain EGH95.

FYI, my radiators' area is about 1,000 sq. ft, and I burn oil to make steam. There is no any feed pump now.

P.S.
I will get the book, however, just to inform myself. I am not in a position to influence a potential installer since the ultimate responsibility lies with that company.

How much warranty on the labor should I expect/ask? The proposals I have now indicate range through 5y, 1y or …none.

Thank you for willing to advise.

Unknown

be careful

The ultimate responsebility is yours. If there were a contractor in the world that had minimal knowledge of steam (how tough can it be?) and bid to work for you anyways, you wouldn't find out until just after HE found out, and left town.

Respectfully, do your homework. The money you save might be your own.

If you need a boiler changed, learn what is to happen, and why, so that you only need to find a good contractor once.

Sadly, the BEST customer, the MOST informed customer, is the one that has to do the job over because he chose the wrong guy the first time. Boy, does HE know what he wants THIS time.

Buyer beware. It's the way to get value for your money, and your time.

One of my favorite sayings is, "If you can't afford to do it right the first time, how can you afford to do it twice?"

I realize it doesn't exactly apply to this case, but in a small way, it indicates that it is less expensive to know what to expect, than to wait and see.

Get references from people that know steam.

Noel