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100 yr old Steam Boiler Coal-to-Oil Converted - Replace or... Help?

Hello everyone,

I'm writing to this forum because I have seen how high-quality and non-biased the replies are. I hope you will be able to help me out.

The subject of this post is a 100-yr old steam heat boiler/classic radiator system that was converted from coal to fuel oil. This car-sized, asbestos-covered monster (you can hear it cycle on from the 2nd floor) goes through ~1900 gallons of oil a year for heat (in the northeast, about 7000 heating degree days). It has a newer burner on it. For my parents, that is about $6,000 a year depending on oil prices.

With the proceeds of the sale of their former home, my parents purchased their final dream home. Although they don't complain, they have had many issues with it, from temperature extremes in the shower (electric tank) and low water pressure to old electricity. Following some work on the waterways of the area by an engineering corp, the neighborhood floods every few years into their basement. The water quality of the point source is no longer safe for consumption, but the village water clogs water filters in 6 weeks and ruins appliances. The truth is that they've spent all the money they did have fixing issues with the house and don't really have much left now. I want to help in a way that actually makes an impact.

The home is about 4,000 sqft, about 9' ceilings, and lots of windows. Half of it is 200 yrs old while the other half is 100 yrs old. There is an unconditioned attic and a basement that does have a loop of steam pipe in it from radiators above it. The brick must be at least a foot thick. There is no insulation to speak of (maybe under the floor of the attic?) and everyone warns against changing the envelope least we ruin the house with moisture and other issues. (I'm still separately looking into attic insulation as an option). They caulk in the storm windows each year.

They tried to space heat by putting in propane fireplaces and later a pellet burner in the basement. In both cases, they used the same amount of oil, just had a propane and pellet bill to add to it. Someone suggested putting pex radiant heat under the floors, but in my limited experience, the cost of adding a whole new type of system instead of upgrading your existing system rarely seems to pay off long-term.

I read on this forum already that descaling, flushing, and other maintenance can help a lot (not sure if any of this has been done yet as my dad does have the Steam Heat manual). What I'd like to ask is if there is something I can do to make the existing system more efficient (I've thought about getting them a new boiler as a present). In particular, my questions are:

1. What do you think the efficiency of this current boiler is? I'm trying to calculate savings by switching, but I'm not sure what I'm working with.

2. Should we upgrade to a newer, higher-efficiency boiler? If so, what should I be looking for? I heard condensing isn't good if your water is like theirs is, but what else should I look for?

3. Should we switch the existing radiators to a hot water system to save money? Would that work?

4. Is there some other approach I haven't thought of that would save them money?

Thank you for your time and expertise!


  • Steam_StarterSteam_Starter Member Posts: 87

    Right off the bat, I would think about replacing the behemoth.  I went thru the same thing when I first bought my home.  We were filling the 550 gal tank no less than 3 times per season, going through over 1200 gallons of oil.  I had some estimates from reputable local contractors and finally settled on installing the unit myself.

    (The old boiler was a Pacific cast iron monster with 8 sections @ about 5' tall each and we just broke it apart at the seams and carried out the sections.  As far as the asbestos, I wont go there...)


    With the new unit installed, living in North Jersey, we go through about 300 gallons a season, if that.  Taking into account the math at todays oil prices @ about $4.00 per gallon we save over $3600.00 per year.  Even if you look at the following items:

    -Asbestos abatement

    -Removal of old unit

    -Inspection of entire system for leaks, new air valves, etc

    -PROPER installation and insulation of new unit

    I am sure that, more than likely, based on the size of the boiler (with the EDR calculations performed) a significant savings in FO consumption will be garnered.  As for the water issue, if the boiler is properly installed and the system inspected / tightened, the water quality will not have an adverse effect.  It just might require, after initial fill, many many many times to be skimmed and flushed which if shown how to do, is not really a difficult task.  it just eats time.  The boil off will remove major impurities from the first fill and then sediment will end up at the bottom of the unit to be flushed out.  It might have to be done repeatedly.

    What to look for in a new boiler? 

    -Get a few quotes from reputable STEAM system installers (check this site)

    -Match the size of the unit to the EDR of the system

    -Ensure the installer KNOWS what they are doing and that they follow the INSTALLATION NOT allow them to deviate or use copper piping above the waterline (they write the IO Manual for a reason...)

    -Insulate, insulate, insulate the piping

    As for increasing efficiency of current boiler:

    You made no mention of venting.  You need to vent the main loop as quickly as possible.  If you posted pics here of what the basement piping looks like and the size / lengths of the runs, I am sure plenty of the pros can assist you in the proper vent sizing and ensure they are in the right locations.

    Check the pitch and the vents of the radiators.  All of the vents should be working and the rads should be slightly pitched to the valve.  Remove vents, clean the nipple and blow into them while the vent is upright; this way you know you have free-flowing air.  If they do not have free flowing air, change the vent...its bad. (Note: don't do it while they are hot! Ha ha...)

    Tighten the system as mentioned  earlier to prevent steam leaks.

    Make sure all of the rad valves are FULLY OPEN.  Partial valve opening on a one pipe system is bad.  (You didn't mention what type of system they currently have.)

    Make sure the boiler water is as clean as you can get it.  You need to blow down the boiler to remove the crud in the bottom of the boiler.  Makes it much harder to create steam when the flames have to transfer heat thru the cast iron AND the sediment.  Again, this may take some time.

    And, as for the house; CHECK THE INSULATION IN THE ATTIC!  This is one of the biggest sources of heat-loss in a home.  My upstairs was noticeably warmer when I removed all of the flattened with age insulation and replaced it with an R-30 foil faced insulation (foil towards warm space; in this case, foil down.) 

    Also, try and find any sources of airflow in the home that you can block off or insulate.  With the age of the house you will not be able to trap moisture in a home of that size unless you cover something extensively in plastic.  You can slow down air movement using a sub strait  that allows moisture to escape but doesn't trap moisture.  As an example, the last thing you want to do is cover an overhead in a crawlspace with plastic.  You will trap moisture on the warm side, thus inducing mold.  There are sheet products on the market that you can use to cover a crawlspace overhead after it is insulated.

    I am sure the pros here have WAY more advice than I do in regards to the heating system.  But from experience, biting the bullet will pay off huge dividends in the long run.  It did for me...

    There are many ways to attack this.  Some inexpensive, some very expensive but it pays to look at all of them, especially with $6000 FO bills...

    Good luck with the endeavor.  More outside advice here if you need it.  This site and the people on it have helped me greatly in the past!

    "Hey, it looks good on you though..."
  • PumpguyPumpguy Member Posts: 272
    Would you

    be able to tell us something about how this system is piped?

     There are many different types of steam systems and they're all piped differently.  Are there any problems with uneven heating, noisy operation,  leaking air vents, etc?

     I'm not an expert in these matters but those that are will need to know the answers to these questions.
    Specializing in vacuum pumps for steam heating systems, especially older Nash Jennings units. We build new ones too!

    Now offering Tunstall air vent valves for steam and hot water hydronic heating systems.

    Please visit our website for more information
  • Steam_StarterSteam_Starter Member Posts: 87

    Pumpguy is right.

    A lot of the boiler info I gave you is based on a one-pipe system as this is what I have..

    I'm biased...

    The more data the merrier!  Overload these guys...

    "Hey, it looks good on you though..."
  • SteveSteve Member Posts: 234

    Replacing the boiler will definitely save money.

    However the warnings of moisture problems if you insulate are based on limited info and myths. Moisture is a complicated subject. Air sealing is the main tool against moisture problems. Getting the house insulated and air sealed will reduce the size of the boiler you need.

    Where is the house located? Many states have no interest loans to upgrade boilers and/or insulation.

    The following link has lots of info that can help.

    Post some pics of the house, boiler and piping.
  • Clock24Clock24 Member Posts: 4

    This is really terrific so far! One of my main concerns was that the money I spend actually DO something, unlike so many other ideas. Sounds like a new boiler could make a big difference (1/4 of the usage!) and I feel badly that my parents wasted money on that pellet stove when it could have been better spent.

    I've keep reading as I waited for responses. Based on other posts and these responses, I'm actually going to have to go see my parents, take pictures, and so forth. Perhaps I can do that this weekend. I *think* it is 1 pipe. I remember that there's a loop in the basement that gradually gets lower and returns to the boiler. I have to check.

    One of my issues is the rural area. A lot of jimmy-rigged approaches and not a lot of experts because it is rural. (Zipcode 12865 - in New York State, but near Vermont border). I checked the site and could only find experts 75 miles away in MA. I am very afraid to find the right person based on what I have read - it seems very important, particularly when sizing. I wondered how many people would even know about the approach I read here:

    I'm building a list: descale, flush out, skim, rebalance, revent/retrapp, tune up, air vents, service valves, Tekmar, insulate mains, add inlet orfices, insulate piping... (By the way, I keep seeing "deknucklehead." I tried to google it and get pictures, but still don't understand what that means).

    Although of course my main question was also the new unit: sized to EDR, no copper pipes. I think we'd leave the old unit in place, asbestos and all. But the new unit - there seem to be many types out there. Any features that really make a difference to longevity and performance?
  • Jamie HallJamie Hall Member Posts: 6,653
    Some overall thoughts...

    and some more specific ones.

    First, the boiler.  Steam_starter's experience is not that unusual.  Good as those big old boilers were, they are nowhere near as efficient -- even with a good burner assembly -- as new ones are.  Therefore... I would be very much in favour of replacing that boiler with a nice new one.  I wouldn't go so far as to say you could cut your fuel bill in half -- but cutting it by 30% or more wouldn't surprise me at all.

    As has been said, do your homework and get a contractor who is really a steam guy, not a plumber.  You mention that you are in the northeast.  Where exactly?  There are several very very good men in the northeast, but it's a largish sort of territory.

    Steam boilers don't condense.  Some newer hydronic (hot water) boilers do -- but you have a perfectly good steam system, and a good steam boiler, properly installed and set up, is within a few percentage points of even the best "mod-con" hydronics.  See more comments below...

    Picky point: when the new boiler is installed, make sure that it is installed with the working water line matching the old one.  Save you a lot of trouble.

    Once you are done with the new boiler, as has been said go over the whole system very carefully.  Make sure you have adequate venting.  Since it is one pipe steam, it is helpful to have the mains vented rather fast, and the radiators much more slowly -- makes much more even heat.  Make sure all the pipes pitch correctly (old houses sag!).

    You can put a hot water coil on the steam boiler, although I have to admit that my preference is for a separate, fuel-fired, hot water heater.  That's a personal preference.

    A steam system, brought up to snuff by that good steam guy, is very nearly as efficient as even the best mod-con hydronic or radiant installations.  There is no need to go to the trouble and expense of installing a completely different system; you won't get the money back (this point has been argued, but... ).  Don't even think of converting the existing piping and radiators to hot water.  You won't gain much, and could wind up with a lot of trouble.

    Now... insulation.  I presume that the attic is accessible, but is unfinished.  That is definetly worth insulating.  Heavily.  What you need to do is to place a vapour barrier between the warm part of the house and insulation, then place the insulation.  An alternative, which isn't quite so good, is if the roof is exposed to use foam in place insulation(such as Icynene) under the roof, which will also block humidity.  The idea is to keep moisture from the house out of the insulation.  Then you can insulate (and here I would very much consider foam) on the exposed part of the basement walls, making sure to seal any gaps at the sills (that's why foam is kind of neat).  I am very much of two minds about trying to insulate the walls, but on the whole I come down on the side of don't do it.  You can't get a vapour barrier into the wall without taking the inside finish material off, which is a terrible job, and without the vapour barrier you can have real trouble with moisture in the walls.  What you can do, though, is make sure the windows are tight.  That doesn't mean new windows.  What it does mean is going around to each window and making sure that the windows fit their tracks properly and don't rattle much, and that they fully close and latch, and that all the trim (inside and out) is tight.  You can also put storm windows on the outside of the existing windows for much less money than replacing the windows.

    To give you some idea, the building which I supervise has 7,000 square feet of heated space, is not unlike yours, is in northwest Connecticut, and uses between 2,000 and 3,000 gallons of oil per year.  It has been treated as I have suggested above.

    Feel free to contact me if you have more specific questions.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Clock24Clock24 Member Posts: 4
    Hi Steve

    Hi Steve,

    I definitely will look into some ways to stop air infiltration. In a brick home, I'm not sure how much we have beyond the windows, basement, and attic, but I'll try. I am concerned about the radon in terms of making the home tight. Given regular flooding, the basement might be an issue to insulate. The roof, though, is something I can pursue.

    I do like that website and was reading a lot on building science. I then went looking for the cost of a deep energy retrofit. I was discouraged by this article ( For a small house, it cost 100,000, payback 139 years. Maybe 50 years here - but still... ripping out all the exterior walls, foaming the brick as they suggest, and putting walls back would just be too expensive and not save enough to justify the expense. Then I read elsewhere about windows - basically saving that if you use storms, there really isn't much in the way of savings with replacement windows that justify their cost. So I'll look into air infiltration if I can find it and attic insulation, but I am also really hoping a furnace will give us a lot of bang for the buck and quickly.
  • SteveSteve Member Posts: 234

    You should have the house tested for radon. If it comes up positive there are ways to mitigate it out of the house but they are not cheap nor should they be skipped. Hopping a leaky house takes care of the problem is short sighted. Also the radon needs to be vented out of the basement not thru the house.

    Yes deep energy retrofits are a bit absurd. However there a re things you can do that will help a lot. Insulating the attic is the biggest bang for your buck. Before this is done all gaps and cracks should be sealed with foam. The space between the chimney and framing should be sealed with sheet metal and firestop foam. I covered my attic with 12" of cellulose and it made an immediate difference, think about adding 14". Home Depot gives you the machine to use free when you buy the insulation from them. I would not recommend fiberglass batt. It is difficult to install perfectly and air can move thru it reducing its effectiveness.

    Get an energy assessment done. They usually bring a inferred camera and it is a real eyeopener to where the problems are.
  • Jamie HallJamie Hall Member Posts: 6,653
    Salem, New York

    By far your best bet is Charles Garrity, 413.841.6726 or 413.243.1683.  He's in Lenox Dale, and it is a bit of a distance -- but you want the best man you can find to do your work, and a little distance (and the money involved) is very much worth the effort indeed.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-McClain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • vaporvacvaporvac Member Posts: 1,512
    Measure EDR to Size Boiler

    I just wanted to point out, that unless you have HW, reducing infiltration, etc, will NOT reduce the size of the boiler you need. The correct boiler size is determined by your square feet of radiation (EDR) ie. your radiators and the piping leading to them. Improving the envelope will, however, decrease the amount of time the boiler needs to run. there are numerous charts on this site that help with this.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • Steam_StarterSteam_Starter Member Posts: 87
    Its a proprietary term...

    Deknuckleheading is a term that is used often on this site.

    Deknuckleheading: verb. removing all the mistakes put into a steam system by people who "thought" they knew what they were doing.

    And Jamie is 100.00% correct. Find the water level on the old boiler (usually mid-point of the sight glass if not marked) and spray paint a line on the wall at the same height. The new boiler water line should match that mark in order to preserve the "A" dimension from the old boiler (if it was correct.) I am sure it probably was....

    And again...insulate insulate insulate!

    "Hey, it looks good on you though..."
  • Don't even think about replacing it

    DEFINITELY REPLACE IT! Sorry for yelling, but don't spend any more money on this fuel hog. In Massachusetts natural gas is much cheaper, so check that out where you live. Stay with steam, its a great system, just get a really qualified installer, because a bad new install could cost more to run an perform really poorly. The wide open passageways of your antique boiler, and the rust and muck built up on the horizontal surfaces, inside your boiler where the heat transfers make this boiler even less efficient than when it was new. Its not uncommon to find and inch or two of rust inside of a boiler this old, sometimes a lot more, try boiling a pot of water with one inch of sand in it, most of your heat is going up the chimney. 100 year old boilers are usually very thick which also slows heat transfer, this boiler may last another 100 years but how much fuel will you waste by then? Install one or two TRV's with the new boiler, and you'll save a ton of money. Massachusetts has zero interest loans for installs like this, perhaps your state does too.

    Thanks, and good luck, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Don't Hire A Plumber???

    Jamie, while I agree a steam install requires a qualified Steam Installer, I don't think you should exclude Plumbers from a list of qualified steam installers. in my neck of the woods the best steam guys are all Plumbers.

    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Charlie from wmassCharlie from wmass Member Posts: 3,911
    Bob don't take it too hard

    Jamie is recommending a plumber to do the job.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • SWEISWEI Member Posts: 7,356
    insulating older houses

    is indeed an art.  Cellulose can usually be blown into wall cavities with relatively little disruption, and it breathes -- unlike foam.  AirKrete is another option to consider.  50 years is absurd - most jobs we see pay back in five years or so.
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