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Need to replace steam boiler.

Merlin Member Posts: 6
We have a stone home built in 1939. We need to replace the oil-fired boiler that we believe is original to the house.  It is a vapor steam system I am told , with copper fin tube convectors.

The biggest waste is the hot water tank that is heated by the boiler.

We are also considering capping off the steam system where it extends to the garage wing of the house and replacing it with propane/ hot water.  We would replace the piping and convectors to radiators and keep that area cooler when not in use.

We invited contractors to give advice and they are so different that we ar afraid to move forward.

All agree that the boiler needs replacing.  The first decision is whether to switch to propane as natural gas is not an option.  I am inclined to at least go with propane hot water and I am very interested in the tankless versions.  No one seems to recommend them, and I am told that we will not recoup any savings on the fuel because of the expensive installation.

We have never had the system run efficiently.  Some rooms are warm but the rooms at the extreme ends of the house are cold.

Contractors have recommended switching to hot water because it does not have to be heated at such a high temperature, but others have said that the system will leak.

We live in Southeastern Pennsylvania.

Amy advice?


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    The system will leak

    Switching a two-pipe steam system to hot water can be a gamble, as the pressures of a hot water system are 10 times higher. The best thing would be to make the new boiler, fired with either propane or oil work properly at mere ounces of pressure of steam.

    Why is the hot water tank a waste? It seems you have some deferred maintenance which when corrected will result in greater comfort and economy.

    The garage wing could be heated with a hot-water loop from the boiler, however any original pipes may need to be replaced with the modern equivalent of pex piping-like a hose pipe which is easier to thread into the old pipe runs than any rigid iron pipe. This zone could have it's own controls, and be controllable separately.--NBC
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    Most problems with cold radiators at the ends of mains

    or long runouts and/or risers, are caused by the misconception that all radiator vents should be the same. That's simply not true. Radiator vents are designed to vent at different rates because they need to vent different volumes of air in the same amount of time.

    First you need to make the mains fill with steam as quickly as possible, by providing adequate main venting to allow the air to escape under low pressure. This allows steam to enter all the take-offs at the same time. Then it's just a matter of providing each radiator with a vent capable of venting its own volume plus the volume of the piping that connects it to the main.

    As an experiment, try shutting off the supply valve to the radiator nearest your thermostat. This will prevent that radiator from heating up and turning off the boiler. Now you can watch how long it takes each radiator to receive steam. If your radiators have the same vents, you can calculate how much venting each should have by timing the arrival of steam. If radiator A takes twice as long to get hot as radiator B, it needs to have twice as much venting.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Rod
    Rod Posts: 2,067
    edited October 2012
    Vapor System Boiler Replacement

    Hi- You're lucky if you have a vapor system as they are the "Cadillac" of the steam systems. The boiler replacement is generally pretty straight forward. The contractor doing the replacement should do a survey of the system first. This means measuring all the radiators and figuring out the total EDR (load) of your system. That determines the heating load and the size of boiler you need.

    Anyone who doesn’t do this in incompetent and you don’t want to use them as they really don’t have a clue about steam systems. The incompetent will just take a look at the old boiler’s output specs and replace it with a boiler the same size. The problem with this is that it relies on the hope the person that installed  your present boiler knew what he was doing. Generally a lot of steam boilers that are in operation today are oversized and having too big a boiler for your system wastes fuel.

      It is extremely important that the piping on the new boiler is properly configured which means the person doing the installation needs to understand steam systems. With the boiler properly replaced, the next thing is to straighten out the system so it operates as it was designed to do.  You mentioned you are in south eastern Pennsylvania. There is an very good steam pro in Baltimore who is an expert on vapor systems. I know occasionally he will travel up into your area.

    His name is Frank Wilsey and he is know by the nickname “Steamhead” on this board.

    Here are is contact numbers: email:   allsteamedup @verizon.net   Phone: 410-321-8116 He’s listed in the Find a Contractor section of this website.  I’d contact him and if he isn’t available, maybe he could recommend a pro in your area that could help you.

    There is a solution for those cold rooms at the extreme end of your house. It is a technique called “Air Locking”.  This technique was resurrected by Gerry Gill ,who is a Cleveland steam pro and like Frank Wilsey, is an expert on vapor systems.  Here is a link to his web page on “Air Locking”


        While you are there you might also want to look around his website as there is a lot of good information on steam heating.

    You might also want to get some of the excellent steam books that are offered on this website. Since you are replacing your boiler I would suggest you get the “Steamy Deal”


    Dan’s steam books are written so someone new to steam can understand them. I would start off with “We Got Steam Heat!” as it explains the basics and the terminology that will help you when you read “The Lost Art of Steam Heating”.  Thes books will save you a lot of money. I can easy say that they have saved me 100 times their initial investment!  

    On the importance of proper boiler piping configuration you might want to take a look at this video:


       You might want to post some pictures of your present boiler. Take the pictures from farther back so they include the piping. That way we can trace out the piping. If we need to see more detail we can zoom in. You might also post some pictures of your radiators (especially the piping as it enters the radiator) and pictures of any "odd" fittings /traps etc,in your system. This will help us identify what type of vapor system you have,

     If you have any questions just let us know.and we'll do our best to help you.

    - Rod
  • Merlin
    Merlin Member Posts: 6
    Hot Water Loop

    Thanks for the repy.  The hot water wast comes from the fact that the boiler runs all summer just to heat hot water.  The oil bills are very high.

    Regarding the loop to the garage wing, I ran your advice past a couple of heating contractors and they didn't seem confident that a loop could be run that distance.  How many loops can you run off of a steam boiler without affecting its efficiency?
  • Merlin
    Merlin Member Posts: 6
    Do you recommend staying with oil

    This is very helpful.  I found your answer after my last post.  I have had more than one person admire the system, and we know it has not run efficiently for years.  We were considering the swirch to hydronic because we were told there would be fule savings.  I do not know if that is the case, but if zones can be achieved by running a loop to an entire wing then the savings would be meaningful.  I will try your referral.  Thanks.
  • Rod
    Rod Posts: 2,067
    Stay with Oil

    Hi- I would stay with oil . Comparing fuels especially oil vs propane isn’t all that easy to do. The first thing to keep in mind is that 1 gallon of  #2 heating oil contains139,000 btus where as 1 gallon of propane contains only 91547 btus. which means you’re going to need 1 ½ gallons of propane to equal the btu content of 1 gallon of  heating oil.

    There are also a lots of addition charges (permits, delivery, fees, rent on propane tank etc.) and applicable taxes that you also have to figure in. If the delivery charge is per delivery then with needing a large amount and depending on the size of the storage tanks you may have more deliveries per season with propane than with oil.

       Last winter the adjusted per btu price for propane was higher priced  than oil. This year it maybe that oil is slightly higher than propane though not by much and that likely to change as ready reserves of oil are high. There are so many local variables that  you have to check closely with your local fuel dealers to see what you would be paying for each type of fuel.

      If it was with natural gas we were comparing, the price differential compared to oil is quite substantial.

      For safety reasons I’m not a fan of propane. Propane, being  heavier than air, if you have a leak, tends to settle in lower areas rather than disperse. Natural gas, being lighter than air, is much less dangerous as it will disperse. 

         For a replacement oil boiler, the Burnham Megasteam is considered to be the most efficient. I've attached a picture of a Megasteam installation to this post. The installation was done by Frank Wilsey, who is the Baltimore Steam Pro I mentioned in my earlier post.


     For domestic hot water, I use my oil boiler during the heating season and switch over to electric HW heater for the summer. I have a large old house though there is normally only my wife and myself so our hot water use in minimal.

    Vapor systems were  designed to operate at very low steam pressure. (Ounces of pressure rather than pounds) so it your steam pressure is now set too high you are using a lot more fuel than necessary.  Typically what has happened to these systems is that over the years proper maintenance either hasn’t been done or has been done in a  “mickey mouse” fashion by heating people who didn’t really understand steam heating. A good steam pro can quickly straighten out the problems and restore a system to its original level of high efficiency and comfort and also suggest ways to further increase the efficiency.

     If you have more questions, don't hesitate to ask. Reading the books I mentioned in my earlier post will help you a lot and you can also find a lot of good information on steam heating in the Systems and Resources sections at the top of this page.

    - Rod

  • JStar
    JStar Member Posts: 2,752

    If Steamhead can't make it out to you, I service eastern PA and would love to see your system and offer my advice. Rod is pointing you in the right direction. Now, you just need somebody who knows how to implement his advice.
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