Converting an oil steam furnace to gas

Mia

In August my Weil McLain SGO-3 steam, oil furnace will be 10 years old, 240,000 BTUs'. I got a price of $8400 inclu permits to install a Weil McLain EG-65 Steam gas furnace.... I thought that was high. Another plumber suggested just replacing the oil burner with a Weil McLain Model 80 Power Flame WCR burner. His price is about $4,000. 2 other plumbers refused to just replace the burner and said it was unsafe. I plan to move in the next few years. Is replacing the burner only unsafe? Seems to me that even with a lower efficiency, by just replacing the burner, I won't recover the full cost of a new furnace. What do you think?

Fizz

Recently converted W-M SGO-6

Last Dec replaced oil burner with Wayne Gas Conversion gun in 11 yr old W-M SGO-6, also had new water heater installed.  Cost was approx 2300.  Very satisfied with performance and efficiency, though it was a mild winter in NE Pa.  Don't know why it would be potentially dangerous, but you will get proper guidance on this site.  I vote yes, but i'm a consumer.  Good luck.

Rod

Oil to Gas Conversion

Hi- I might mention that one of this board's rules is that we don't discuss pricing.

   Changing over to gas is basically just  a matter of switching out the burner. Oil boilers are wet based and with a power gas burner, are very efficient.

 You need a steam pro.  Let us know where you are located. You might also want to take a look in the "Find a Contractor" section at the top of this page. Scroll down to the States section and see if someone is listed near you. In my experience, all steam pros are good plumbers, however, few plumbers are good steam pros.  There is nothing unsafe about switching over to gas as long as it is done by a competent pro.

- Rod

Mia

OIl to gas

Sorry but the purpose of the $$ quote was asistance on whether it paid to replace the whole furnace or just the burner.  The 2 plumbers says that just replacing the burner & reusing the oil boiler is unsafe and I should install a completely new gas furnace...  I wanted confirmation on whether that's true.  To me it appears that the cost differential is substanial but I don't want an unsafe situation.... I'm located in Jersey City in northern NJ.

Steamhead

Rod is right

We do NOT discuss pricing on this forum. For any reason.



The gas burner we would use on the smaller SGO is either the Carlin EZ-Gas or Midco EC. Are you sure that's an SGO-3? The BTU rating sounds high.......

Rod

Oil to Gas Conversion

Hi- I understand what you are trying to find out, it’s just that NO discussing dollar pricing is a steadfast rule on this website.  I won’t take the time to go into the reasons why but if you’ve been on this board a while it makes good sense.



The following is just some notes I put together that maybe of help to you.



Heating Terminology - Just so there is no  confusion, a furnace heats air, a boiler heats water.  Boilers heat  water to produce hot water for hot water heating systems and domestic (tap) hot water and they can be setup to produce steam for steam heating systems.  From what you have told us you have a steam boiler.



In converting an oil fired steam boiler to gas fired, the following needs to considered



1. The burner conversion - This means the materials and labor for replacing the oil burner with a gas burner.



2.Gas piping - What is needs to be done to supply natural gas to the new burner.  If the present gas piping is of sufficient capacity the cost of materials and labor should  be fairly minor. However if the present gas system is severely undersized this could add quite a bit of cost to the installation.



3. Chimney - On switching over to gas you will need to have you chimney inspected  and  possibly have a stainless steel liner installed.



4.Oil tank removal - The old oil tank needs to be removed and  properly disposed  of.



Items # 2 to 4 would  need to be done on either a just a gas burner conversion or on the installation of a complete new gas  boiler.



 The advice you got on conversions being unsafe is absolutely not true.  It sounds like the persons giving you this advice are either incompetent and/or trying to sell you a whole new boiler package.  I see Steamhead has replied to your post. He is a Very experienced  Steam Pro and has done a LOT of  this type conversion.  You might want to check the specifications plate on your boiler to double check the model type. It also might be of help to post some pictures of your boiler and the attached piping so we have an idea of how your system is laid out. Take them from farther back so we can trace out the piping.



If you don’t already have a copy there is a very good book on steam heating called:  “We Got Steam Heat!  available in the Shop section at the top of this page.

http://www.heatinghelp.com/products/Steam-Heating-Books/25/61/We-Got-Steam-Heat-A-Homeowners-Guide-to-Peaceful-Coexistence

   It’s easy, entertaining reading and written so the homeowner new to steam  can understand it.  A couple of evening’s reading will put you light years ahead in your knowledge of steam heating. My copy has saved me a lot of money and has easily paid for itself a 100 times over.

If you have more questions, don’t hesitate to ask and we’ll  do our best to answer them.

- Rod

Fizz

Conversion lapse

I want to apologize for my indiscretion re:$, it was uncalled for and I know better.  I've been a member for a few years, and find it to be not only the best site for heating help, but one of the finest of all sites on internet.  Again my apologies.



Fizz

Mia

Oil to gas conversion

You're correct.  The model as listed on the furnace is a A/B SGO 7 (w),  240,000 BTU - steam.....  My owners manual said SGO 3.    From the comments it seems that just replacing the burner to a gas fired one will NOT be unsafe and the loss of efficiency will be minimal, correct?  I prefer to re-use my current boiler but don't want an unsafe condition.  Unfortunately as a female homeowner, I have to double check everything...  I appreciate all the timely responses & will get that booklet.  Again apologies on the $$ quotes.  I found this site thru a google search....

Mia

Oil to gas conversion

You're correct.  The model as listed on the furnace is a A/B SGO 7 (w),  240,000 BTU - steam.....  My owners manual said SGO 3.    From the comments it seems that just replacing the burner to a gas fired one will NOT be unsafe and the loss of efficiency will be minimal, correct?  I prefer to re-use my current boiler but don't want an unsafe condition.  Unfortunately as a female homeowner, I have to double check everything...  I appreciate all the timely responses & will get that booklet.  Again apologies on the $$ quotes.  I found this site thru a google search....

Rod

Converting Oil to Gas

Hi Mia-

   Most residential boilers are made of individual cast iron sections which bolt together like slices of bread. Adding more sections results in a larger boiler with more steam being produced. On  the SGO model- The SGO7 would have more sections that an SGO3.  

   The typical gas boiler sits over the gas flame just like a pan of water on a gas stove.  An oil boiler is a wet based boiler which means that the water being heated surrounds the burner flame.

(See attached diagram) The oiler burner has a pump and air blower which produces a hot flame.



There are two types of burners used for gas. One is the atmospheric which is just like a gas burner on a stove and the other is a gas power burner which has a blower to provide more air for combustion.  You asked about efficiency of your conversion. Many of the pros consider a wet based (oil) boiler with a gas power burner as being more efficient that the regular atmospheric gas burner. Several boiler companies,(Smith and SlantFin) come to mind) offer wetbased boilers with a gas power burner. With oil prices going up there are a lot of people converting their boilers to a gas power burner so doing this conversion is pretty common.



It isn’t just female homeowners who need to double check everything. Most of the homeowners (including me) came to this website because something they were being told just didn’t sound quite right. I’m glad to hear you are getting “the book” as it will really be a big help to you. Most of us started our adventure in steam by reading it.  One of the things it does is give you enough knowledge to know if the heating man you are talking to really knows anything about steam heating and unfortunately very few really do.

 

What you need to look for is a good steam pro who understands steam and burners. To properly adjust the burner he should have a digital combustion analyzer so that the burner can be tuned to maximum efficiency.  The old adage “You get what you pay for” really applies in the heating business.  Go for competency rather than just the lowest bid. 



Take a look around in what is know “Off the Wall” in the Resources and Systems sections at the top of this webpage. There is a lot of good information available there. Here’s a video on the importance of peoper boiler piping that might be of interest to you.

http://www.heatinghelp.com/article/107/Steam-Heating/118/Steam-boiler-near-boiler-piping



Don’t be afraid to ask questions, that’s how we all learn!

- Rod

Steamhead

We just installed a new SGO-8

with Carlin 201Gas burner.... runs great!



http://www.heatinghelp.com/forum-thread/141630/Weil-McLain-SGO-8-with-Carlin-201Gas

Mia

Converting Oil to Gas

hello Rod,

Thanks for the detailed answer.  I looked at the videos... interesting...   I should watch them by my furnace, provided my wifi will reach, so I can compare the piping to what I have.

In your opinion, do you think the Weil-Mclain 80 Power-Flame burner model WCR is a good fit for my WM SGO-7 oil boiler?

Thanks for all your assistance..

Mia

Rod

That's a Question for Steamhead

Hi Mia-  

   As a homeowner I really don’t consider myself qualified to answer specific questions on burners. With all his experience, Steamhead is probably one of the best persons to answer the question in your last post.



      Weil Mclain is a boiler manufacturer and doesn’t make burners, either oil or gas.  In residential burners, Beckett, Carlin and Riello are probably the most predominate and each makes a range of both oil and gas burners. Powerflame also makes good burners. 

     One of the things that concerns me is the size of your boiler.  It’s a pretty big boiler for the average house.  How big a house do you have?  You mentioned that someone quoted you on an EG-65. Did that person go around and measure all the radiators in your home? That is the correct way to determine the size of the boiler you need.   It pretty common for boilers to be way oversized so if he just looked at the figures on the spec plate on your present boiler and choose on the EG-65 based on that, he may be just duplicating the mistake the earlier installer may have done 10 years ago when he put in your present boiler. Oversized boilers burn more fuel.

     This is all explained (far better than I ever could) in “We Got Steam Heat!”  All this may seem a little overwhelming at first but it all falls into place after reading “the book”.



Tell us a little more about your steam system- Is it one pipe or two pipe system?

- Rod

Mia

My system

hello Rod,

The house is a 4 story plus a full cellar, 17 ft wide by 40 or 50 ft depths, 1880s' attached brick brownstone with a 2 story extension with flat roofs. The crawl spaces have been insulated. On 3 floors the ceilings are at least 9 ft  to 10 ft high.  It's only a 1 pipe system attached to cast iron radiators.  Ten years ago I contacted a plumbing supply house and I counted all the fins on all the radiators and the technician calculated the size of the boiler and recommended WM.  He also recommended the plumber, who I had already used for other small jobs.  At that time I was just on the cusp & decided to go with the larger boiler ( SGO 7) since I had cold spots & was thinking of adding another radiator.  I never did but the top floor is a bit cool but luckily my tenant prefers it that way.  It gets noticeably cooler as you walk up the stairs.  It's a one thermostat house which is located in my dining room, which has the 10 foot ceiling.

The plumber who did the job 10 yrs ago, suggested that he send out one of the supply guys to measure the house, as opposed to counting fins, but he will not just replace the burner but wants to install a new, gas boiler.  He and another plumber mentioned that it was unsafe to just replace the burner.  He also suggested a smaller boiler.  Considering my top floor is cool, I don't think so.  The valves have been replaced several times and should be Ds'.

I currently have a Beckett burner,  The plumber who recommended  the WM 80 burner mentioned it's a commercial grade one.  The spec sheet mentions it works for gas, light oil or combo gas/oil firing. He did take the BTU's off the side plate.

Thanks again!

BobC

Cool 3rd floor

You mentioned you were nervous about using a smaller boiler because of heat issues on the 3rd floor. In steam systems you need to produce enough steam to fill all the radiators, the name plate on the boiler lists the rated sq ft of steam the boiler will produce and that will include enough padding to include normal piping issues. Using a boiler that is to large is inefficient and really won't do any good in your situation unless you plan to substantially increase the number of radiators.



Have your heating men looked at the venting of the system to make sure it's working ok? Steam can't fill a pipe or radiator till all the air is expelled, the best route is usually to vent the  mains fast and the radiators more slowly. That way the steam should reach everything about the same time. Maybe the issue is in the main vents, do you know what kind of main air vents you have now?



You mentioned all the valves have been replaced "and should be D's" The D is a very aggressive vent, they are usually used pretty sparingly. If someone suggests replacing all of them with D's it sounds like the main vents are not working right OR you piping has some improper slopes in it. It would be best to sort this out before deciding what size boiler to install.



Are all the radiator air vents the same? Can you post pictures of the main air vents and a picture of the different air vents you have on the radiators? Pictures of the piping above the boiler might help also



Bob

Mia

It's a cool top, 4th floor

The top 4th floor, 5 floors in total if you count the underground cellar where the boiler is located, has Ds', the 3rd fl has Cs' etc....The 1st floor, which is slightly below grade has the smallest valves....  I'm not sure where the main valve/ vent is.  I noticed one in a small linen closet on the pipe that goes to the top, 4th floor.  The individual vents on the radiators are " J Steam Air valves, Maid-O-Mist, 1/8" angle", round ones.  I get them at Home Depot/Lowe's.

But I really only want to replace the burner and use my existing boiler to convert to gas....

Rod

Converting Oil to Gas

Hi Mia-

   Thanks for the description of your home. I was concerned about the size of your boiler as my home is an old 3 story wooden one in central Maine and my boiler is slightly smaller than yours.



I would be a bit concerned about the plumber “who did the job 10 years ago” as indications are he may not know much about steam heating.  You don’t measure the house if you are just replacing the steam boiler. If you were building a new house or changing over the heating system to another type, you would need to measure the individual rooms do determine heat loss so that you could then install the correct size heat emitter. The heater emitter being the heating element for that room. (baseboard hot water, electric radiant, floor radiant, steam radiator etc.)



In the case of replacing the boiler on a steam system, the emitters (the steam radiators) are already installed so there is NO need to measure the room’s heat loss!  The steam radiators can’t put out more heat than their size/design  allows so all you have to do to determine the new boiler size is determine the total heating capacity of the installed emitters (the steam radiators) and match the boiler to that.   This is done by measuring the radiators to determine each radiator’s heat output (EDR) If the person replacing your boiler doesn’t measure the individual radiators, it is a pretty good sign he really doesn’t know what he is doing.  As previously mentioned,  just looking at the spec. plate on the old boiler is the “blind following the blind” especially so if the earlier installer also didn’t know what he was doing!  



For more info on steam systems your might want to take a look at Gerry Gill’s website:

http://www.gwgillplumbingandheating.com/



I see in the Find a Contractor section that Gateway is located in Orange which I believe is fairly close to you. http://www.heatinghelp.com/professional/60/LOOKING-FOR-A-STEAM-HEATING-EXPERT

You might want to discuss with them what your options are. I’m sure they could do the conversion for you.

- Rod

Steamhead

That PowerFlame burner

is too big for your SGO-7. It's made for the W-M 80 series, which is a small commercial boiler.



I would use either the Carlin 201Gas (as shown in my other thread) or the Midco RE4400DS burner in your boiler.

Mia

That PowerFlame burner

hello Steamhead,

Thanks for that info!  I will pass your comment along to the plumber or find another guy.  Thanks again!

best,

Mia