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Weil Mclain vs HB Smith steam gas/oil

xpressman Member Posts: 1
I have a 2 years old Weil Mclain sgo4 oil fired burner, is it possible to replace only the burner with a gas burner? I got the feeling I could freeze to death this coming winter since I wont be able to afford $5 to $6/gallon heating oil this winter.


  • Hollis
    Hollis Member Posts: 105
    Weil McClain vs H.B. Smith steam gas/oil

    A little nervous to convert my old oil boiler to a new gas one.
    I understand that the flame from nat gas is not as hot as oil and wonder if its going to be a problem with a fairly large 5 unit apt house and the dynamics of its piping.
    It seems to be (finally ) balanced now both in mid winter and the warmer Spring/Fall weather.
    I was going to ask for a HB Smith 8 series that COULD be converted back to oil fired if things didn't work out but my heating guy (Hudson NY) doesn't "do" HB Smith and likes Weil McLain which I understand is also a good boiler and they have a EG seies that also can be converted if necessary.
    Any reason to NOT go with either of these choices or is there a preference that you might have if it was going into your property?

    Also Question #2,..this is an old 155K boiler, Since I got the building we have installed storm windows (incredibly it only had single panes when we got it, also was able to install more insulation in the ceilings and some walls. So I'm wondering how this works about measuring radiators and the size of the new boiler. Wouldn't the addition of this insulation (and tightening up after/with ) a blower door effect this formula? Thank you for any input.
  • tim smith
    tim smith Member Posts: 2,765
    Re: steam boiler questions

    You still have to look at sq ft of radiation for your sizing. HB smith or Weil Mclain I would say will be ok. I know Steamhead likes the Smith boiler a little more and I think I like the design better. I have not used a Smith yet on a job but have done Weils and Burnhams over the years. I think I like the Smith design better. I am going to use one here very shortly on a job.
  • Choices

    First, the EG steam boiler is gas only, it cannot be converted back to oil. So I'd rule that model out, based on your preferences.
    In regards to sizing the boiler, steam boiler capacity has been greatly reduced in large numbers of installs if, and, this is critical, system balance is addressed. This is contrary to conventional wisdom, but there have been articles in industry publications citing hundreds of such systems in commercial properties in New York city alone, where boiler capacities have been reduced well below conventional "connected radiation" sizing, saving on replacement costs and fuel usage.

    The procedure for reducing boiler capacity below existing radiation is well documented for two pipe systems and involves working out room by room heat loss numbers so the existing radiators can be "resized" to current needs. Resizing radiators does not involve removal and replacement, but the installation of orifice plates in the supply valves that meter the steam at the proper rate into each radiator. This procedure follows the same design strategies as many of the best vapor type heating systems (very low pressure steam systems) ever invented. Also, I would look over the system piping to be sure there are not any sizing issues that effect steam distribution. The steam boiler is then sized by the heat loss numbers and the amount of heat necessary to compensate for piping system losses.

    I "undersized" my first steam boiler about seven years ago for an old Moline brand vapor system that already had the orifices built into the supply valves. After restoring the system and installing the new boiler, I made some balancing adjustments with the valves and now the system heats the home very evenly ( the second floor used to be quite cold) and very economically, with a boiler at about half the capacity than the one it replaced. For my boiler sizing I bumped the capacity of the boiler slightly to help provide quicker system warm up.

    If you have one pipe steam, I have not undersized boilers greatly, but leave out most of the pick up factor. I have seen very old installations where th boiler is quite undersized and the homes heat very evenly and economically.

    I have yet to find a clear procedure for "undersizing" boilers, but two general directions. The steam mains must have plenty of venting and the radiators must be vented very slowly. This combination helps prevent steam from entering the radiators because there is very little air escaping the raditors vents and directs the steam to the ends of the mains where the air escapes easily on boiler start up. This largely follows good one pipe steam practices. At this point balancing the radiators to the heat load in each space and to each other must be done. Since venting must be slow, I use the lowest venting rate adjustable vents that I know of, the Hoffman 1A's. I have yet to use a setting more than about 3 on the largest radiators, and then go down from there. One pipe steam balancing is much less scientific and simply experimental, but I do start with largest vents at the highest heating needs and/or radiator venting needs, and work down from there. This again is conventional wisdom.
    When completed, both systems will heat up more slowly and with long burn times (just like when the coal fired boilers were used as most steam systems were designed for), providing very stable room temperatures and even heating.

    I would contact Tunstall Associates for information on two pipe systems, as they have available design tables and can point you to articles published on this subject.


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  • klaus
    klaus Member Posts: 183
    Weil McLain Model P-SGO-3 Conversion to Natural Gas

    Help :)

    I have a Weil-McLain Model P-SGO-3 Series 3 Furnace which as I'm sure you know has a coil. Also, I have steam heat (radiators). I am thinking of converting to natural gas and was curious as to whether or not this would be possible with this particular furnace. I have been told I would definitely need to install a hot water heater. Any insight would be greatly appreciated!!

    Thanks much!
  • Unknown
    you call ur boiler a furance?

    You will need to start a new tread with this question but please don't call your boiler a furance.... :)
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    would the \"dead men\" agree?

    this is a very interesting concept.i hope i did not make the wrong choice when the installer of our choice actually measured the radiation [all 60 of the radiators] and sized our new peerless 211-a to that radiation load.
    the other competing proposal was based solely on the capacity of the 1971 american standard-no measurements!
    naturally if you had a dual boiler setup with the combined capacity split into a 40%-60% arrangement you could drop one boiler out when you had reached the ideal [low] operating steam pressure.would it then be able to operate without the 40% boiler firing at all?
    it may depend on the size of the building and it's flywheel effect ,and the local weather patterns whether you can get by with undersizing.if you have sudden decreases in your temperature [as we can have in the great plains] then the time taken to reheat the building might give rise to complaint.
    at any rate i think that most steam systems would benefit from a hi-lo burner, which i am determined to install on our boiler.i can see that, once pressure is up; that it can be maintained when i partially close the ball valve in the gas train.as a result the gas meter turns 25% slower when i do this,and there is less cycling [anyone see the tour de france?]--nbc
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