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How to convert steam boiler (EG) to hot water boiler?

Bill Julian
Bill Julian Member Posts: 128
Any info on this? I installed new W/M EG steam boiler last year and now the customer wants me to convert to hot water. I get all the piping but any info on the wiring? I probably need to add an aqua stat, remove pressure trol and LWCO, gauge glass and change boiler relief. But the wiring. How is the aqua stat wired in to the new system?
Does it wire into the boiler circuitry using the pressure trol wiring?

Thanks for any help.

Comments

  • Steamhead
    Steamhead Member Posts: 15,654
    You need to think long and hard on whether you really want to take that job. Unless you're completely tearing out and replacing the steam radiators and piping, something is probably going to leak- remember, hot water runs at over ten times the pressure of steam. And guess who will be responsible?

    Also, a hot-water radiator only puts out roughly 2/3 of a steam rad of the same size, so the house might not heat well- and guess whose fault that will be?

    Sometimes it's best to just say no. Given the pitfalls, it's very possible you'll lose money doing this.

    Why do they even want to convert?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    ethicalpaulHVACNUT
  • Bill Julian
    Bill Julian Member Posts: 128
    The entire system is being removed. Rads, piping all of it.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    Leave the low water cutoff, even hot water boilers should have them. Take out the pressure control and install at least 1 aqustat, I would install two of them. 1 a manual reset high limit and 1 operating aqustat. Install a magnetic dirt separator. Flush the boiler and get as much muck out as you can
  • ethicalpaul
    ethicalpaul Member Posts: 3,905

    The entire system is being removed. Rads, piping all of it.

    And replaced with what?
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • Bill Julian
    Bill Julian Member Posts: 128
    The Eg boiler is staying being converted. The system will be FH baseboard with 2 zones.
  • ChrisJ
    ChrisJ Member Posts: 13,555

    The Eg boiler is staying being converted. The system will be FH baseboard with 2 zones.

    Hey Bill,

    Can you share a picture of the boiler for us just so we know we're all on the same page?

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Henry
    Henry Member Posts: 995
    Converting the boiler is a no-no. The boiler looses certification and YOU become responsible for any hiccups and damages. Depending where your are, the AHJ can come after you. It is cheaper and more efficient to get a mod-con of the proper size calculated by a proper heat loss.
    Steamhead
  • Bill Julian
    Bill Julian Member Posts: 128
    Never heard of such a thing. Conversions are possible. The size is closely compatible to the heat loss. The boiler is 1.5 years new he's not going to change a new boiler.
  • Jamie Hall
    Jamie Hall Member Posts: 19,954
    Look. Bluntly, this whole job is a catastrophe. "Saving" the boiler will save some money, potentially -- although in view of the overall cost of the job -- it's minor. Nor is it the best way to do the job properly. Your consumer will be much better served if you spec. and install a properly sized mod/con, starting from scratch, rather than cobbling something together.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Henry
  • Bill Julian
    Bill Julian Member Posts: 128
    Ill inform you that after calling Weil Mclain they gave complete go ahead for a conversion as it reads right in their literature. C ya later
  • KC_Jones
    KC_Jones Member Posts: 5,259
    I've never really understood the "logic" of these conversions. If they don't like rads, it's cheaper, in the long run, to buy a house without them instead of incurring all the expense of installing a new system.
    If the steam is having issues the knowledgably contractor should be correcting the problems for their customer as that is far cheaper than a complete system replacement.

    It's their bank account that's getting drained not mine.

    I guess some people just like to spend money?!

    Also, some homeowners are simply misinformed and make poor decisions due to bad information, or possibly bad work influencing those decisions. Many possibilities.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • ethicalpaul
    ethicalpaul Member Posts: 3,905
    I guess you're gone, but if WM said it's OK in their literature it seems like they could tell you how to do it successfully?

    I'm sure several folks are curious why a brand new steam install would have to get converted to water but that ship may have sailed...
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • Steamhead
    Steamhead Member Posts: 15,654
    Henry said:

    Converting the boiler is a no-no. The boiler looses certification and YOU become responsible for any hiccups and damages. Depending where your are, the AHJ can come after you. It is cheaper and more efficient to get a mod-con of the proper size calculated by a proper heat loss.

    Henry, the EG boiler is approved and sold as both a steam and a hot-water boiler. It says so right on the rating plate. You might want to check W-M's website next time.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    I don't see anything wrong with what he is proposing to do

    he has a boiler that is only 1 1/2 years old. The EG is listed for water or steam. Pull up the manual it's the same manual for W or S so that is a moot point

    Some people don't like big cast iron radiators, they worry about kids getting burned or the radiators are ugly whatever, I don't agree with that but if they want water and new radiation then that's what they want.

    Steam requires a little hands on work from time to time and some homeowners are not going to do that.

    be happy he's not going scorched air
  • Bill Julian
    Bill Julian Member Posts: 128
    edited April 2021
    I think some of you are not properly informed. The steam boiler is 1.5 years old that is true. But the homeowner is not changing the system because it is not heating, or dirty or noisy or undersized. The steam system is having no issue, running great plenty of heat. He simply wants to go HW. The big radiators are an issue and also the very hot radiators are rather painful to children that touch them, other than that he wants the system changed.

    Weil Mclain literature specifically says and the tech rep specifically said, the same steam boiler can be converted to hot water easily. In fact, it is designed that way with little set back.
    There are steam boilers you can not convert, I get it, but this is not the case. You mentioned brand new steam system, it is only the boiler that is new, 2 feet above it all the way to the 2nd floor is 60 plus years old.

    Anyway folks thanks for taking the time to give your views. I'm good.
    Dave T_2
  • jumper
    jumper Member Posts: 1,906
    Depends on how tall building is. Head over 15psig requires ASME stamp.
    pb_sam said:

    If the existing boiler is in good condition and able to withstand the maximum water pressure of the proposed system, then it can be converted to be compatible with the new system rather than replaced

  • Dave T_2
    Dave T_2 Member Posts: 64
    edited April 2021
    There is no reason you should not convert this boiler to fhw. WM sells that model as steam or water. Here's WM control wiring intructions https://weil-mclain.com/sites/default/files/field-file/EG%20PEG%20EGH%20Control%20Supplement%200915%20WEB%20Version.pdf

    Let me know if you have any specific wiring questions.
    Bill Julian
  • Jamie Hall
    Jamie Hall Member Posts: 19,954
    I think we've probably lost our OP on this one, as he seems to think we don't know what we are talking about.

    So... a comment and question. This sort of situation is or can be a real dilemma for an engineer or a tradesman. What does one do when one is faced with a client who knows exactly what they want and won't budge, and you know that they are either ill-informed or just downright stupid -- to put it bluntly?

    I know what I did when I was a practicing engineer -- tell the client I wouldn't take the job -- but I was busy enough in those days that I could afford to do that, and we are still busy enough in the house caretaking racket to do that. But what do you do?

    Mostly curious.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,654
    The customer doesn't want the cast iron radiation. A lot of people don't. Seems dumb to me but it's the same as the ones that want an "open concept" floor plan.

    The boiler is only 1 1/2 years old and Weil lists the same boiler for water or steam.
  • ethicalpaul
    ethicalpaul Member Posts: 3,905
    Or the boiler install has "issues" and the customer has been told "that's just the way steam is"
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG