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Oil to Gas steam system in Boston

Hi all I have peruse the site on this subject but I am still confuse since I am a newbie.
New home owner moved in right after Christmas in a two family in Boston came home this weekend to water in our basement and no heat in our unit.
We have two oil one pipe steam system, the Plumber came and told us the boiler is dead and need replacing.
We were planning to change them to gas in the spring/summer but got to do it now.

Unit 1 is about 1099 sq using a oil weil mclain gold series with a separate water heater. (that's the one that leaked)
unit 2- about 1300 sq got an older oil thankless system will post the model and picture later. This one is currently working but older than the unit 1 system that leaked this weekend.

Here's what I am looking for help with. The previous owner build a bathroom in the basement with no permit and the job was done poorly. they raised unit 1 flue pipe for head room clearance and it drop on its way to the chimney after the bathroom.
-One contractor told me they can power-vent it outside so it would not have to go though the chimney. But I've read on here that a lot of folks don't recommend it.
-another contractor said they can run a smaller pipe and go around it and still has enough elevation to the chimney but their quote is more than five figure more. or they mentioned that the bathroom woodwork can be taking down at additional cost.

I would like to keep the bathroom and renovate it down the line, it is really a bad idea to power vent the outside?
Unit 2 system is right next to the chimney so there isn't much issue with that one other than the fact that we'll now have to get a water tank for it I am told there is no gas all in one unit as currently existed there.

also any difference between a Burnham vs a Williamson Thermoflo boiler?
Anything I should look out for?
Would love to hear from you great folks out there what I should be on the lookout for. Just brought you got steam on amazon but won't be there for a couple of days, trying to learn as much as I can.

Thank you in advance


  • KC_JonesKC_Jones Member Posts: 4,557
    jaybee80 said:

    Anything I should look out for?

    I can't comment on the venting, but in answer to that question, yes. Have any of the contractors measured all the rads to size the boiler according to that? By my guess (with 2 boilers) you will most likely need the smallest ones made for steam, but again all radiators need measured to size properly. Never size off of the original unit. Are the contractors you are looking at good steam contractors? Have you asked for pictures of their installs to see what kind of work they do on steam? If you get pictures post them here and we can tell you if they know what they are doing or not. If they get it wrong you will be paying for it. Have any of them asked about comfort? Even heating? Any issues with the current system? Did it heat silently and evenly? These are all things they should be asking you.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • FredFred Member Posts: 8,500
    Additionally, Whatever you decide to buy, make sure you look at and understand the pictures of the near boiler piping, Header, risers, equalizer, Hartford or Gifford loop, wet returns installation. Many will take short cuts that will cost you in performance/effeciency from day one. If they are able to use the existing wet returns, make sure they flush them out well. Is the chimney a common chimney for both boilers? If so, are you converting both boilers/water heaters to Natural Gas? If not, I'm not sure you can mix oil and Natural gas in the same chimney. Others on here will comment on that. Also, a lot of municipal codes require a chimney liner when converting from oil to gas. Maybe direct vented boiler(s) (out the side wall of the building) might be an option ?
  • jaybee80jaybee80 Member Posts: 9
    Thank you, for your response. One did go around and measured the radiators, the other two just walked around and looked at them. No one asked us about comfort. We've only been in the house for less than 3 weeks and it's been pretty warm in Boston until this passed weekend, the house is well insulated, even now with no heat the temperature as stayed in the mid to high 60 with a couple of electrical heaters and when we turn them off at night the dropped of is not that great with the exception of this morning. It's freezing here in Boston today.
    and when we cook the place stay warm for in the 70 for hours.

    I will asked for picture and reference for their work. I am interested in hearing about people view on power-venting one of the boilers outside compare to going to the chimney.

    The discrepancies in what I am been quoted is also unreal I have two offer near each other and one from (both local businesses) and another from a bigger outfit that sent a sales person way way above the other two.
  • jaybee80jaybee80 Member Posts: 9
    not sure what you meant by that "By my guess (with 2 boilers) you will most likely need the smallest ones made for steam"

    I am planning on changing both boiler from gas to oil and we have steam system in both unit.

    thanks for the your info I will make sure to write those terms you mentioned learn more about them.
    (make sure you look at and understand the pictures of the near boiler piping, Header, risers, equalizer, Hartford or Gifford loop, wet returns installation)

    the chimney is currently being use by both oil boiler, my dilemma is this. one of the unit is close to the chimney and another for the first floor is seperated by a bathroom that was build in the basement by the previous owner. they raised the pipping from the boiler to make head clearance and it dropped on it ways to the chimney. that's is why i was contemplating having that one power vented with the new gas boiler to the outside to resolve that issue .
    The chimney will be lined up as part of the conversion at least for one of the boiler right now. trying to decide if I should do it for both and move the bathroom when we able to renovate the basement down the line.
  • jaybee80jaybee80 Member Posts: 9
    @ Fred

    You said (Maybe direct vented boiler(s) (out the side wall of the building) might be an option ?)

    Do they have Steam boilers that direct vent to the outside?
    My understanding is that is not the case. Maybe someone can clarify that for me?
    thanks again
  • KC_JonesKC_Jones Member Posts: 4,557
    It doesn't go by square footage of the building, but of the rads. My meaning was you have relatively small units and most likely will need the smallest boilers made, or close to the smallest. So be weary of anyone recommending anything big. As a double check you can do your own EDR calculations on the radiators (fairly easy) so you know what you should be expecting. Boilers are over sized so often it's crazy. Bigger isn't better.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • FredFred Member Posts: 8,500
    A flue should have at least a 1/4" rise from the appliance all the way to the chimney. Any flue that has a dip in it is dangerous and needs to be fixed. I don't know what the requirements are for a power vent but a direct vent can eliminate the use of the chimney all together and may be a viable option.
  • jaybee80jaybee80 Member Posts: 9
    Ah I got it. one quote I got they didn't even list what size burner that will be put it. it just mentioned two Burnham PIN4SNI-ME2 Steam boiler.
    the other listed a Williamson Thermoflo GSA125 EI
    and 150EI for the bigger unit

    Yeah that is our issue, the flue dip because they build a bathroom between it and the chimney they lift it a bit to get head clearance I am guessing. It's obvious no permit was taking for this. This came up during inspection and we knew we had to fix it. just happening much quicker than we plan.
    I see only two option, I would like to keep the bathoom and update it at some point because it's nasty and we won't be using now. or remove the bathroom work work and run the pip correctly but will will have to move the bathroom to a new location down the line. when we do some work in the basement.
    which will probably add to our cost to that future work
  • Chris_LChris_L Member Posts: 201
    edited January 2016
    I've got a 2-family outside of Boston, and looked into replacing both boilers last summer to take advantage of rebates then being offered. I ultimately decided to keep my 30-year old boilers, which are working fine.

    I looked at both the boiler models you listed, and here is my take. Both of the Williamsons are likely much too large, at 325 and 392 sq. ft., respectively. The connected radiation of my two units, which are somewhat larger than yours, are 165, and 205 square feet, respectively.

    The Burnhams are probably closer, but likely still oversized, at least for your smaller unit. You should check out the PIN3PV at 163 square feet, too. And as others have mentioned, get an accurate measure of the connected radiation and find an installer who will install a boiler to match. (I found this to be almost impossible, everyone wanted to oversize.)

    Since the Burnhams you were quoted can be power vented (but it looks like the ones in the bid are not), that might eliminate your chimney problem. Note also that if your existing boilers are over 30 years old, you may qualify for a rebate but I think you may have to wait until the spring.
  • jaybee80jaybee80 Member Posts: 9

    Thank you very much for your post, unfortunately I do not have the luxury to wait, I will have to look for information on here about how to measure for an appropriate size boiler.
    but as I mentioned earlier we are currently living without any heat since the weekend (we living in the smaller unit) since the boiler cracked, and I am planning on renting the second unit as soon as it is ready so I am trying to use the mass save program to do both heating system as I would hate to be having issues with the other unit boiler which been acting up as well (I have found low water level in the working boiler for the past few days after I put some in the day before).
    Our only saving grace right now is the fact that the boiler in the upstairs unit is working. I put the temperature a little high so it can run more often and that in turns keeps the basement pretty warm even during these last couple of very cold days here. I am doing that because we are worried about frozen pipes.
    I just came home and my unit temperature was at 58 now its up to 62 it will probably get to the high 60s now we cooking dinner and using the oven.

    I talked to a family member earlier who strongly advise me to try to get a systems that vent outside for both the boiler and water heaters.
    Do you or anyone else as any feedback regarding going such route?
    Thank you once again
  • BobCBobC Member Posts: 5,170
    Direct venting is a last option in my opinion, they are not cheap, they require yearly maintenance, and they will fail at some point. A properly lined chimney is very reliable and has no moving parts. Think about the problems you may be letting yourself in for before going down that street. If this half assed bath is really a crap hole it might not be worth saving.

    As far as what size boilers to install, make a list of the radiators each boiler feeds and find out their EDR rating. Add up the EDR's for each boiler and get something that is about the same rating.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • jaybee80jaybee80 Member Posts: 9

    Ok I am including the pics of my boiler and my ventilation dilemma, the failed boiler piping to the chimney was raised to by the previous owners so they can build a bathroom in the basement. the bathroom itself is disgusting and what they did to the flue is illegal and probably dangerous as well but I would like to eventually redo the bathroom and run stairs from my unit to the part of the finish basement to create a playroom/entertainment room when we can afford it.

    This is why strongly thinking of having the boiler vent outside instead of removing the bathroom woodwork as been mentioned to me by one of the proposal I would like in the future to redo the bathroom and raise the head clearance in there which is low right now

  • jaybee80jaybee80 Member Posts: 9
    Thank you for the advice Bob, I am torn on that subject. I have read similar concerns regarding power venting for steam like yours but I was also told by a very close family friend that I should vent every thing out boiler and water heater and to eventually get ride of the chimney if I decide
    He mentioned he did the same at his house 10 years ago now and never had any issues. I do trust him as he is a semi retired contractor only managing his own property and someone I trust and that I know would look for my best interest.
    But your point is well taken and is making me really give this a lot of thought
  • Chris_LChris_L Member Posts: 201
    I can't comment on the reliability of the power-vented Burnham boiler. I don't have one, but other readers may be able to weigh in.

    One thing to consider is the noise level, with two of these boilers running at once, particularly if you live in the downstairs unit. But if you are switching from oil burners, that may not be as much of an issue.

    The other is any remodeling plans you might have. If yours is like many other 2-family homes in the Boston area, the chimney for the boilers is in the wall between the kitchen and the dining room. If you ever want to open up the kitchen to the dining room, you'll probably want that chimney gone. If so, probably best to get the boilers out of it now.

  • jaybee80jaybee80 Member Posts: 9

    That is very true, I am only giving this a lot of thoughts because some of the good people on here as brought up the issue of maintenance cost associated with power ventilation.

    Thank you so much for the chart. Greatly appreciate it.

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