Oil steam boiler converted to gas... what next?

Stuie

I have an oil steam (one pipe system) boiler that has been converted to gas.  Perhaps it's time to move on.  I found a near high-efficiency gas steam boiler 82-84% AFUE. 

Am I on the right track and if so, are these boilers so sophisticated that I need someone with "near high efficiency" steam installation expertience to gain the most benefit? 

What about power venting and it's effect on AFUE and maintenance costs?

Charlie from wmass

boilers made for gas are better

There are 2 on the market now Slant-fin and Smith. I like Smith and STeam head likes Slant-fin. and we both would put in either if the job called for it I would say. The boiler is not hard to install but some installs get complicated when iot is installed. If you get a guy who knows steam he will have no issue with a power gas burner.

Unknown

Best Gas Steam Boiler

As Charlie mentioned, the consenus on the most efficent gas-fired residental steam boilers seems to be the Slant-Fin and the Smith G-8. These are "wet based" oil fired boilers that are also factory approved for use with power gas burners. Steamhead, one ot the most experienced pros on here, claims "their thermal effiency is roughly 6% better that the usual atmospheric steamer."  The advantage to the boiler be "wet based" is the flame is surrounded by boiler water so there is better thermal transfer. For oil, the Burnham Megasteam leads for efficiency. Unfortunately Burnham hasn't approved it yet for gas.

 I would get an experienced steam pro to set it up for you. You need some one with the know how and experience plus instrumentation to set it up properly. Charlie is in Western Massachusetts and Frank, "Steamhead" is located near Baltimore. They are probably two of the most experienced pros on these units. If they aren't local to you, check at the top of the page in "Find a Professional" as there are a lot of good steam pros listed there that could help you. In "Find a Professional"- Scroll down the pages till you see the States listed and check under your state. The software has been recently updated and is still a little "buggy" so that quite often trying to find someone by zip code isn't successful.

- Rod

Gordo

Thank You, Rod

Again, for the kind words for my outstanding partner.



Just want to add a little something, if I may.



The main reason we install Slant-Fin is because they back their products to the hilt.  Because of that, Slant-Fin is second to none in our book.



My advice: install a Slant-Fin. Period.



Smith boilers, as boilers, are good products, as far as that goes. The problem for us, is their local rep.  They treated us as if we were a waste of their time, and were absolutely no help at all when we had a problem with a Smith boiler.  We got the feeling that the rot went deeper than that. 

nicholas bonham-carter

taking care of the customer

what a difference a good local stocking rep of a concerned manufacturer makes to the end-user as well!

when we had "hidden water" problems, peerless tech support, and the local peerless rep gave it their best shot to help find the source of the problem.

however, in the end it was Noel Murdough  on the "wall" where i finally found the answer!!!!!!!!!!!!!!!!!--nbc

Charlie from wmass

Yep local care is what counts alot.

The reason for us using Smith is the same as Gordo and Frank using Slantfin. Just as a good installer makes for a better boiler a bad installer drags down the best of boilers. Also a bad rep makes for an unhappy installer. Smith was made 40 miles from our door for many years. They better treat us well as we can knock on their door if we have an issue. Which we have. Install enough boilers and you will get a lemon no matter the brand. It is how they stand behind it that matters most. I am sorry Frank and Gordo do not have our Smith rep, maybe I can get him to travel to Maryland?

Charlie from wmass

Gordo you can always send me the names in private.

I would be happy to explain why the boilers are not moving in Baltimore to the folks at Mestek.

Stuie

thanks for the help and thoughts

Thanks for the kind help and thoughts. 

Whether Slantfin or HB Smith, mention was made that a power burner raises efficiency over atmospheric gas burners.  Are the high AFUEs provided in corporate literature reflecting testing with power burners?

With a gas power burner as suggested with a wet based boiler of Slantfin or Smith will I see 82-84% AFUEs?  Or 6-8 more?   It is a small home 1 1/2 stories, completely insulated and  720 square feet on the first floor in Hull MA.



thanks again,

Stuie

Charlie from wmass

The boilers are rated energey star.

I find them to fire between 84 and just over 85 depending on the model. Smith is bad at publishing literature or advertising their G8 boilers. Infact unlees you go to their literature page there is no mention of the boilers on their web site.

Gordo

Thanks, Charlie

Please check your e-mail

alcraig

boiler choices

It may be asking the same question as Stuie, but why are these boiler manufacturers marketing atmospheric gas boilers as their gas boiler and their wet based boilers as power oil burners only?

You really don't find any of them (Slantfin, Smith, Peerless) offering a power gas burner boiler. Is that because a power burner costs more and they're trying to market competitively?

If so, what do you pros usually do...order a boiler and a gas power burner (such as heatwise or beckett) separately and construct the system yourselves?

Looking at the Smith website I see the Oil Series 8...is that the G8, (setup with a gas burner) that you mentioned?



Sorry for all the questions...just learning.

Thanks.

Steamhead

Marketing is part of it

also resistance to change- this trend is new enough that not everyone has jumped on board yet. 



The first residential wet-base/gas power burner combination I ever saw offered from the factory was the Solaia hot-water boiler with the HeatWise SU, about five years ago or thereabouts. When I looked closer and realized the thermal efficiency was better on this setup than on an atmospheric, I realized this was the way to go. But it was only recently that the Solaia people added the gas option to their brochures.



Then, almost by accident, I found the Smith 8 boiler (both steam and water) being sold as the G-8 when equipped with the Carlin EZ-Gas. After that, I found Slant/Fin had done their gas burner certification on the Intrepid (which includes the former Liberty series if you want to convert one of these to gas) using the SU, EZ-Gas or the Midco EC burners. Again, the thermal efficiency is better.



Years ago when fuel was cheap, a 6-7% improvement in efficiency wasn't worth it to many people if the more-efficient boiler cost a bit more to buy. Nowadays, we don't have the luxury of cheap fuel, and we never will again. So if you have a cheap boiler installed you're still going to pay for the cost of a better one- you just won't benefit from it. This will undoubtedly become more obvious as fuel costs rise.



So the wet-base/power gas burner option is to be preferred over the atmospheric. Another advantage is that it can usually use a standard chimney (with liner of course) in a building where sidewall venting is not feasible or safe.

Steamhead

Stuie, what boiler do you have now

and what burner is in it? 

Stuie

MY current boiler

To Steamhead:



I currently have a Weil/McLain oil steam boiler with a gas conversion gun...at least I think I do.  I am in DC and not home.  My guess is that it's 15 - 20 years old.

Thanks for asking,

Stuie

Stuie

full circle

So we have come to an interesting point in the discussion of Gas/Steam

I already have a wet based oil cast iron steam boiler converted to gas and now the discussion seems to have arrived to the point that such an equipment set may be the best set up except:

1..has boiler design improved significantly to justify the boiler and burner change?

2. has the burner technology alone improved so that just changing the burner is the most cost effective choice?

3.  what about the efficiency gain with matching power vent damper...? 

4.  Can that be added to the current boiler?

As I was not the homeowner during the changover of oil to gas I suspect it came from a the gas utility selling against oil pricing at an earlier time time when the gas cost/Btu was doing well against oil as it has been in the last years.

As the homeowner it's all very interesting.....

If replacing the boiler/burner is cost X then replacing the burner alone is likely about .20-.25 X and then adding damping (if it can be done will add .15-.20 more so that the combination is nearing 1/2 the cost of total replacement and, of course, the boiler is already 15-20 years old and is nearing its own demise by age ..maybe another 10 years??/

Steamhead

That will depend

on which W-M boiler you have and what burner is in it now. Let us know when you get home, then we can give you a good answer. 

Charlie from wmass

The question was raised as to why power burner wet base?

The atmospheric boilers once were fired with millivolt systems and could run if they had water without the need for electricity. Also they are quieter. My father prefers the atmospheric boilers due to less moving parts and a quieter boiler. The 2 to 4 percent gain he does not feel is worth the extra noise. I am finding the new atmospheric boilers are not as trouble free as they once were. Gas valves not lasting 20 or 30 years, dampers not functioning so well, and ignitors needing changed. I figure they all are wearing out and needing parts, why not use the one that burns the least fuel. Also with so many chimneys failing the power burner helps with that. The difference between a converted boiler and a new boiler with a power burner is the burners are made for the boiler specifically. The boilers are nice and clean and free of soot and other nasty stuff including the 20 years of sludge clogging the innards. This makes the boiler that much more efficient as it is not just how the fuel burns but also how well the heat can conduct to the water to form the steam.

Steve Garson_2

Keep your present boiler

If you already have a WM wet base boiler and gas burner, I wouldn't change a thing. I would make sure the boiler is completely cleaned and the burner combustion is set to the optimal settings with instruments,If your steam boiler is twenty years old, not much has changed, from an efficiency perspective, for gas compatible boilers. The more efficient ones require oil, at least for now. Focus on making sure you have good venting on the mains, low pressure and good combustion. The return on your investment just won't be there. If the boiler was failing, that would be a different story.

jpf321

slant/fin intrepid on gas?

Steamhead --



When I was at Slant/Fin today (http://www.heatinghelp.com/forum-thread/129089/visited-Slant-Fin-today) I asked Stacy, Dir. of Sales and Marketing dept, specifically whether the Intrepid was rated for gas .. and she said NO. She said there is not a gas gun for the Intrepid.



I see in this thread above that you mention Slant/Fin obtaining their cert for Gas Intrepid...(and in the other thread of mine in the Gas forum) you recommended I look at the Intrepid TR-30 due to the ability to convert to gas at a later date

 .. now I'm confused again...I'm not saying anyone is wrong here, more likely Stacy is misinformed ..  I will email John S. at Slant/Fin, Dir. of Technical Services, and ask him for his take.

jpf321

bump

nudge for the morning readers

Stuie

Bang for the buck

My boiler is a WM  oil/steam boiler A8  468 of 1987 vintage.

It was designed for 465 square feet of steam with an 149 MBTU input/ 111.8 MBTU output

And it was retrofitted with an Economite E20 Gas burner.



So: 

1,. In the best of circumstances and ideally adjusted what is the likely AFUE?

2.  From a cost benefit standpoint what is worth doing?

a.  Just keep it well adjusted

b.  Replace burner

c.  Replace boiler



Thanks to everyone for their thoughts and help....this blog is superb and the folks on it as well.

Stuie

DavidK_2

I'm no expert,

but here is my opinion anyway.



Likely your boiler is running at about 80% (maybe a little more) based on flue gas measurements. You might want to have a pro come over to make sure this is true.



The new boilers might be a little more efficient. Maybe 85%.



Is the 5% worth it? Maybe - you'd have to do that calculation for yourself.



As Charlie points out the other issue is how much of that heat is actually going to make steam, and heat in your house. I don't know how you quantify this. A heating system is a system - you can't look just at burner efficiency you have to look at the whole system. This is not as easy to quantify.



My plan is to hold on to my old boiler as long as it keeps working relatively well. Who knows what might be available in a few years. I'm guessing better than what is available today - but I could be wrong.