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Retrofit old steam system

Hello to you all. I must admit that I have no knowledge of steam heating systems This will likely become apparent right quick. But I'm always willing to learn.

I have a 100 year old farmhouse - moved to a new location and a new foundation. It had a one pipe steam boiler system with radiators in each room. The radiators have mostly beeen disconnected but I was wondering if that system could be reconnected.

Question 1: There is presently in place an set of hot/cold insulated underground plastic pipes coming from an outside boiler/furnace room - we wanted to have the combustion unit separate from the main house - to supply heat to the house.

Can these plastic pipes supply steam heat or is that too much for them?

Question 2: Can any steam system use plastic piping or must it be iron pipe?

Question 3: Could the one pipe steam radiators be changed into a two pipe radiant system using the existing steam radiators and therefore lower operating temperatures?


  • Steamhead
    Steamhead Member Posts: 16,888
    Might want to re-think the outside boiler

    you lose a lot of heat between the boiler and the house.

    At present, plastic pipe cannot handle steam. But I suppose anything is possible if one is willing to research it.

    If the steam system is still there or mostly there, hooking it up should be pretty easy. I wouldn't try to run hot-water in old radiators like that- even if their design would allow them to work with HW, the greatly increased pressure might cause them to leak. Same with the old steam pipes

    Post some pics of what you have and we'll take a look. Also, where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • dansfarmhouse
    dansfarmhouse Member Posts: 2
    Old steam

    Thanks Steamhead. I didn't think that plastic could handle steam temps but no harm in asking. I think that pretty much nixes the whole idea because we don't want a fossil fueled appliance in the house.

    The house is located near Calgary, AB.

    Steam boilers just aren't meant to carry HW, eh? I was thinking of them as radiators instead of a flat baseboard type, seeing as how we still have all the units.

    The vertical pipes are all still in from the basement to the second floor, though I don't know how functional they'd still be. The house was being used with this system about 5 or 6 years ago.

    The basement is unfinished for getting pipes to the first floor radiators, ie. there are still holes in the finished floors where pipes went up.

    The walls have what I'm told is seaweed insulation, it sure looks like it could be seaweed, sewn into packets about 3 or four inches wide between two pieces of heavy craft paper. The attic only has a century of fine dust as insulation. The previous owners must have spent a bundle for natural gas.

    In a steam system, can each room be zoned and have its own thermostat?

    Are there hi-efficiency steam boilers, eg. condensing boilers, that approach the efficiency ratings of the new gas furnaces?
  • Steamhead
    Steamhead Member Posts: 16,888
    edited October 2009
    Some radiators

    were designed for use with either method. But there are others that were designed for steam only. These were a bit less expensive to make. If we could see some pics we'd know what you have.

    I'm curious why you wouldn't want a boiler in the house.

    90%+ is possible on steam but North American boiler makers are really dragging their feet on this. Plus, in your area you'd have to locate the intake and exhaust for such a boiler well above the highest recorded snow accumulation. I'll bet that's higher than some houses ;-)

    A steam system will give you far better comfort than a scorched-air fur-nasty system ever will. Distribution efficiency is better too. The typical duct system loses something like 20% of what goes into it. You could have a 90%+ furnasty, but what's the advantage if 20% is lost in ductwork?

    Unlike a hot-water system, most of a steam system drains completely dry when it shuts off. The only pipes holding water are in the basement and the boiler itself has water in it too. So if something goes wrong (power failure, fuel interruption, etc) and the building drops below freezing, the system will sustain little if any damage.

    You can use thermostatic radiator valves on steam radiators as limiters for rooms you want to keep cooler than the main house, such as bedrooms or guest rooms.

    And insulate that house well! The most efficient heating system is the one that doesn't have to come on.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Books on Steam Heating

    If you have the radiators and most of the piping in place it wouldn't be hard to hook it back up. Steam is a really good heating system when you get it running properly. It's a pretty simple system though you have to take the time to understand it. If you're interested in steam heating I'd suggest you get two books. They are available on this site. One is "The Lost Art of Steam Heating"


    and the other is "We Got Steam heat!"


    These will bring you up to speed on steam heating. They are easy to read and in a few evenings you 'll know far more about steam heating than most people in the heating business.

    - Rod
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    how true that is!!!

    The most efficient heating system is the one that doesn't have to come on-from steamhead!!-nbc
  • Jamie Hall
    Jamie Hall Member Posts: 23,421
    There is no good reason

    other than efficiency to not have a steam boiler in a different building from the one you are heating.  Think of all the central steam heat systems there are, all over the country!  However, if you are going to do either steam or hot water -- it doesn't matter which -- and run the lines underground from one building to another, you will want to take major precautions against heat loss.  You could do a cost-benefit on options, but in my humble opinion, the best approach would be to run the steam (or hot water) lines and returns inside a separate duct, rather than directly buried -- and insulate the dickens out of them.  I'd go with 2" on the feeds, and 1" on the returns.  I would place insulation over the top of the duct -- again, 2" -- and extending out at least as far to each side as the depth of burial.  Overkill?  Not in Alberta...  You have the advantage with a duct, too, that you can run the power and control lines for the boiler in the duct as well (at least I think the Canadian electrical code permits that; I'd have to check).

    Got to admit I wouldn't do it -- but then, it pays to remember that the client is always right...

    On the other set of topics -- it will be more satisfactory to reinstate the steam system.  There is no reason at all why the risers -- if they were in use only a few years ago -- or the radiators should give any particular problems (I have seen buildings where steam was supplied to a system which had been off and abandoned for 40 years -- and it worked fine from the get-go).  That will be much easier than trying to convert to hot water.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Steam

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