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Carlin Gas Conversion or new oil tank?

I currently have a 1 pipe steam system with an oil fired Weil-McClain boiler. I've been told it could be 15-20 years old, it's a blue one not gold. Size AB-366E HE series 3.

I've owned the house for 7 years and the boiler has been regularly serviced (since I've owned) and I'm told it still runs at about 83% efficient.

The problem is my 50+yr old oil tank is starting to develop a small leak and it's time to replace it or convert to gas. The new oil tank would cost me about $2200 but I would get $1000 back from tank insurance, so $1200 OOP.

I've had one contractor (recommended by gas compay) come and say the boiler could be converted using a Carlin Conversion Burner & I'm waiting for a quote from him.

There is already an active gas line in the house that runs by the boiler to the dryer, but he told me he had to check if the size was big enough for both or if they would need to run a new line. Also I asked about the chimney and he recommended getting it inspected for a gas burner.

One important thing to note is I don't plan on being in this house for more than 2-3 more years if that long so I already think that eliminates the option of replacing the whole boiler with a new gas boiler (especially since there are no rebates for steam boilers). So I'm trying to make a smart decision based on me trying to sell the house in the next couple years.

Anybody have advice on Carlin conversion burners put on Weil-McClain steam boilers? Will this be more trouble/money than it's worth and I should just buy a new oil tank?

Western Mass Steam Homeowner


  • heatpro02920heatpro02920 Posts: 991Member
    edited March 2014
    gas saves money

    In most cases with the current prices per BTU, gas will save you money, I personally would try to sell you a new gas fired boiler vs a conversion burner.

    I haven't had great luck converting that boiler, personally I found the wayne burner works best in there, but I would say you are throwing good money after bad, the cost of a conversion will be a good portion of installing a properly sized gas fired unit...
  • FWDixonFWDixon Posts: 78Member
    I am by no means a pro

    But I do have a Hot Water boiler that uses a gas-conversion burner and the half a dozen or so local folks I have talked to also recommend a purpose-built gas boiler over a conversion burner.
  • icesailoricesailor Posts: 7,265Member
    edited March 2014

    I'm not suggesting one way or the other.

    But your Weil-McLain P366 has one short chamber. Be sure that whomever suggests a conversion burner checks to see if the gas conversion burner will fire into a boiler as small as that. For a 3 section boiler, it is only 9 1/2". Because it is a steam "AB" block, it might be 12 1/2" because a "AB" boiler is just the block and not a package boiler. I always used "AB" blocks because they gave you more choices in how you piped them. IE, return in the back for better flow circulation through the boiler.

    I also doubt that if the boiler has been properly cleaned regularly, some of the sealant between the sections may be gone. It is not practical to repair it. IMO.

    If it was mine, I would burn up the oil and have everything set to switch to gas.
  • Tim McElwainTim McElwain Posts: 4,248Member
    Your boiler is a good

    candidate for the new Carlin EZ Pro conversion burner, have it converted just make sure whoever does it has experience with gas conversion burners.
  • SteamheadSteamhead Posts: 13,117Member
    I agree

    with Tim. 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • heatpro02920heatpro02920 Posts: 991Member
    Hey Tim and Steamhead,

    I haven't been on in a while, how are you guys?

    I have had less than perfect results converting the 3 section WM's and Williamsons, he tight firebox if everything isn't perfect, I have had some impingement issues and with steam I had some issues not being ale to get the BTU's needed... I use the wayne burner and ended up getting them correct in the end, but not as easy as others I have done...

    By the looks of his boiler and going by my prices, I would say unless replacement with a purpose built gas boiler was way out of budget it wouldn't be a bad idea, I have replaced similar oil/steam boilers of the same model a long time ago, and I fear that one may not have a long life ahead of it {only going by my experience, it could be in great shape and last forever, by from what I see, its probably not the case}.

    I am going to give that ez burner another try, I actually have a conversion Wednesday of next week {pending a signed proposal}, so maybe I will use a carlin instead of the wayne, {So Tim expect a phone call if I get hung up on anything :) }...
  • icesailoricesailor Posts: 7,265Member
    edited March 2014
    3 inches:

    What a difference that 3" would make (the difference between a 366 and a 466)

    They stopped selling *68's in the early 1990's when they came out with the Golds.

    They stopped selling *66's in the 1980's. That boiler is well over 20 years old. The tank less cover gasket is leaking. The burner plate is leaking exhaust gasses on the top. Very few that you can still read the red plate above it. That is one well maintained boiler. Not like a lot I have seen.

    Like I said in the beginning, I care not in any way. But when that thing goes, it will be quickly. But it sure is nice to see something that is well taken care of.

    The Wall Street Criminal Enterprise and their energy trading arm is gonna' get us anyway. Before I replaced any oil tank, I's be looking at some nice gas Steamer that has a consensus of opinion here that it is spiffy.  

    I just replaced my AC. The duct work was shot, 30+ years old. The rest was 20 years old. The last thing I wanted was for the OK running system to take a dirt nap in August. Sometimes its just time to say good by to old friends.

    And get rid of all that copper tubing on the supply risers. I'll bet there's "Issues" with the operation that would go away if it had a properly installed header and such.
  • Tim McElwainTim McElwain Posts: 4,248Member
    edited March 2014
    I would venture to say that

    the boiler will probably last another 10 years with a Carlin EZ Pro the new Carlin Burner. I wish that the near boiler piping could be changed as copper is not a good idea on steam. All of the conversions I ever did required some refurbishing of the existing boiler, including perhaps a new fire box or at least a target wall in the chamber, removing the outside jacket and checking the sections for proper sealing, and in the case of steam making sure all the controls etc. worked and did not need any maintenance.

    Part of the issue with replacing oil steam boilers with gas atmospheric steam is the efficiency is much lower do to high excess air requirements.

    This boiler looks like it has been maintained and with some gasket replacement etc. it will go 10 more years.

    I looked back at my records and I have converted 27 of these over the years. I took a chance and called one of the customers that had the conversion done eight years ago (Carlin G3B) and it is still running with good efficiency. The customer is more than happy with the long term operation. The only service has been to replace a hot surface igniter three years ago. The boiler is given annual maintenance by one of my trusted service companies here in this area.
  • Tim McElwainTim McElwain Posts: 4,248Member
    Hi Heatpro

    The Wayne burners are not a good burner for that application as the flame pattern is too long and impingement is probable. You need a burner like the Carlin EZ with the shorter flame pattern and still giving adequate BTU to satisfy maximum firing rate.
  • Chimney liner & BTU

    Thanks for all the replies. I would have to check the service records but I had some work done in the "chamber" or firebox within the last few years as some of the insulation and seals needed replacement and that cast iron burner plate (my terminology is probably wrong but oh well) was getting so hot it was glowing. Since that service the boiler has been running without issue and from what I can see no leaking or obvious signs of problems.

    Reading that red plate to get the size is tough but I think it says 109/BTU per hour, is that what the boiler is actually running? How do I know the BTU's it's currently producing?

    The chimney inspection people want to know what the BTU's will be for a new gas burner or (whole new gas boiler), they say it will effect whether I need the chimney lined with stainless or if current chimney is ok as is.

    I've also been told that if the new conversion burner is within 95% of the BTUs of current oil burner than I can safely avoid lining the chimney. Does this sound correct?

    As far as the near boiler piping, I know it was never supposed to be copper, but it's been there for 15-20yrs now so is it really worth removing now if I just do the carlin burner? If I replace the whole boiler I would make sure the piping is fixed but is it worth messing with it if I'm leaving the old boiler?

    Thanks for all the help, I'm learning a lot on this site.
    Western Mass Steam Homeowner
  • heatpro02920heatpro02920 Posts: 991Member
    Thats why you make the big bucks Tim...

    I am going to try that next week, keep your phone on incase this thing starts whistling ....
  • heatpro02920heatpro02920 Posts: 991Member
    btu for conversion burner

    I would probably look at your service record to see what burner btu to run, take your nozzle size say .85 gph and pump psi and do the math to find what your input is... then use that number and look at the efficiency readings to get the number that will show you your output..

    use pump psi and nozzle size to get amount of fuel per hour {input} then use the efficiency to show your actual output...

    This is considering your boiler is running the radiators satisfactory....
  • SteamheadSteamhead Posts: 13,117Member
    I would use

    the 9-slot diffuser on the EZ-Gas, as it gives the shortest, most compact flame. 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Tim McElwainTim McElwain Posts: 4,248Member
    It is my

    procedure to do a heat loss, then measure square feet of radiation and then look at what the oil guy was firing the unit at as far as nozzle size and pump pressure. That will bring us to a starting point as to input, then an accurate combustion test will allow you to fire the boiler at its maximum designed firing rate. This can then be adjusted by using the pressure regulator on the gas valve.

    As for the lining on the chimney ANSI Z21.8 Procedures for the Installation of Gas Conversion Burners requires a liner with all conversions since 2002.

    I've also been told that if the new conversion burner is within 95% of the BTUs of current oil burner than I can safely avoid lining the chimney. Does this sound correct? THAT RULE IS OUTDATED AND ANSI Z21.8 APPLIES.
  • Charlie from wmassCharlie from wmass Posts: 4,070Member
    Is conversion worth it?

    Has  every one looked at the photo of the installation? This is a typical Springfield copper no header no equalizer boiler that is a couple decades old. The 95% rule still applies in Mass. Just went over it in CE class.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Last service record

    Attached is a picture I took of the print out from the last service call I had in December. Will this help tell me the BTU's I'm currently running at? I don't know what formula I need to use for this.

    Here are the readings show in the attached picture in case you can't read it.

    CO2 Max 15.7%

    Flue Gas -

    482.7 F T-Stack

    10.53% CO2

    - 0.0783 in H2O draft

    82.7% EFF

    59.0 F ambient temp

    0ppm CO ambient

    45.8% ExAir

    6.9% Oxygen

    Not sure if any if these help tell the BTUs my boiler is currently outputting?
    Western Mass Steam Homeowner
  • Tim McElwainTim McElwain Posts: 4,248Member
    Find out from your oil

    man what size nozzle (GPH) you have on the burner and what the pump pressure is. That can be calculated to give you input.
  • icesailoricesailor Posts: 7,265Member
    Excess Air:

    "" "45.8% ExAir" ""

    With that amount of excess air, some might think that the section sealing is shot. Along with the front cover gasket. And the cleanout cover gaskets on the top. 

    With those other numbers, the efficiency should be higher than 82%.  
  • Charlie from wmassCharlie from wmass Posts: 4,070Member
    Ice now you see

    why I recommend a new boiler not a conversion burner.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • New gas steam boiler

    With a new gas steam boiler I was told the best efficiency I can expect is at most 85%, so I didn't think 82.7% was that bad.

    I'll have to ask my oil guy about the GPH and pump pressure because I can't seem to find it on my own.
    Western Mass Steam Homeowner
  • Charlie from wmassCharlie from wmass Posts: 4,070Member
    that efficency number means less than you think

    That 45% excess air means there is 45% not 33% excess air pumping through your boiler and up the chimney. also I tell you what I can check the combustion for you tonight and see if that number is even real. Call me I will be free after 5:30
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Oil burner

    I'm waiting to hear back from my oil guy on the pump pressure but I did find this attached sticker on the burner from '09 when I had some work done on it. Also in '09 they installed a new chamber kit, air tube and end cone. I've been pretty happy with everything since then...except oil prices of course.
    Western Mass Steam Homeowner
  • heatpro02920heatpro02920 Posts: 991Member
    edited March 2014
    almost 46% ex air

    do yourself a favor and listen to the guy in post number 2, lol... I would take Charlie up on his offer...
  • icesailoricesailor Posts: 7,265Member

    You didn't read ME suggesting a conversion burner. If I recommended someone spend that kind of money for the installation of a conversion burner on a 20+ YO boiler, competition would call me a crook and a fool.

    Once I realized how easy it is to blow the sealant from between the sections on those 66/68 boilers, I hardly want to recommend cleaning them thoroughly. After vigorously cleaning a GO boiler, the same effort will destroy one of those with a soot saw. Like I almost did with one. Fortunately, I was able to repair it.

    There's something that they say to diabetics about testing your blood.

    "You can lie to yourself,

    You can lie to your doctor.

    But you can't lie to your meter.

    The same applies to a properly running digital analyzer. The print-out doesn't lie. Yu could get all kinds of interesting results with a wet kit. That all went out the window with my Insight. The only thing I still used from my wet kit was the draft gauge and the smoke tester.
  • heatpro02920heatpro02920 Posts: 991Member
    I agree 100% charlie

    Unless finances will not support a new boiler vs a gas conversion, not sure about other peoples prices but with me its not a huge difference between the two when you factor in

    A-you get a new boiler,


    B-either way a liner will be needed unless you power vent.

    I have passed on gas conversions like this in the past, I have a friend of mine that owns a local company and will install anything, I recommend him and walk away.

    I have spoken to the op in PM's and he may just stick with oil, sometimes this is the best bet, if the unit is running good, hold off until you can afford to change the unit out the rite way, liner and a nice new shiny boiler... you wont be sorry..

    I remember a while back when the parts support for the 1725 burners was fading away and in many cases it was a more affordable to upgrade to a 3450 burner and change what would need to be changed than repair the old shell head... I had a few upset customers when their boilers only lasted a few years after the new burner, long story short I gave my share of $750 discounts for 2-3 year old burners that were only $500 new....

    Conversion burners are a nice option, I just finished a riello conversion burner {special order, took 5 months to get!!!! I'm lucky the customer still wanted it} on a g215, worked great, and was a great option since the boiler was 4-5 years old and is a REALLY nice install {ask me how I know that ;) lol} plus its stacked on top of a buderus indirect {not in a hurry to change that boiler or tank}....

    So the conversion burners should IMO only be used when a new boiler is absolutely out of the question financially, unless the boiler is in really good shape not very old and will take the conversion well.... Steam installs are normally more affordable than FHW installs, and judging by the condition of the existing unit in the OPs basement, I would strongly recommend a new unit..

    Anyway, I have played my broken record enough, good luck with which ever road you take, new boilers and burners are fun, pull up a chair and watch how much fun your contractor has changing them....
  • Charlie from wmassCharlie from wmass Posts: 4,070Member
    I have not seen repeatable results

    when I test steam boiler with my meter unless I test with a cold boiler before the water boils. It may be a new trick in my area but I often find the efficiency off several points when I test a boiler at or near boiler compared to the print our that is next to the boiler. Yes my meter goes in for regular tune ups and I carry the wet kit just incase my readings seem off with the digital and I want to double check.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • icesailoricesailor Posts: 7,265Member
    edited March 2014
    Stack Temperatures:

    Probably because the stack temperatures keep climbing. 482 degrees F? Was it steaming?

    One reason you always get better numbers with a hot water boiler. Set the high limit to 160 degrees and you can immediately have a potential 40 degree drop in stack temperature.

    IMO, that boiler will never run and read all that well because of all the leaking going on. If it was a SGO, it would be as tight as a tick. New or old.

    Most old 66/68 boilers I have cleaned had serious air leaks on the top cleanout plates. I used to fix that with a piece of a Lynn wet blanket. They usually leaked around the front burner plate, making the red boiler rating plate unreadable. Then, there's that air adjustment on the left below the burner. I guess you were supposed to open it if the burner rumbled and you couldn't make it go away. I've found them in all types of positions. Open or closed. Where ever I found them, I always left them. I wasn't taking the risk that something might go wrong and I would have to go back.

    I had a few rumblers. The rumble always went away when I put in a EZ-1.  
  • Charlie from wmassCharlie from wmass Posts: 4,070Member
    wider angle on the nozzle

    I had a couple boilers this year that I tried a wider nozzle angle and the rumble went away. Same GPH, Same pattern, one angle wider. no rumble. It was nice. If it was an SGO I would already have the burner on it and running for the guy. And worry about fixing the near boiler piping in the warm weather.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • icesailoricesailor Posts: 7,265Member
    Dangling Angles:

    If the burner was the same as the one on the boiler in question in this string, you went from a 80* to a 90* spray? Or did it have a 70* and you changed it to a 80* spray?

    Many of the rumbler's I found recovered when the proper 80* nozzle was installed. They usually had 70* nozzles installed. Its my experience that that fixed head burners is only really happy with the proper 80 degree nozzle. The ones that couldn't be fixed had other issues. Mostly a lack of consistent draft.
  • Chimney inspector

    Thanks for the offer Charlie, I wasn't home till late last night but I'll call and see if your available tonight or Thursday.

    Below is what the chimney inspector told me about lining my chimney, they confirmed what Charlie stated about 95% of BTU being in code but said I may still eventually need to line the chimney.

    Thanks again for all the help/info, I'm continuing to research all my options as I burn down what could be my final tank of oil.

    "As I explained to you, the current code allows a conversion without relining the chimney as long as the tiles are in good condition (which your are), AND the BTUs are not changing from the BTUs you currently have venting into the chimney. The only future problem is that the BTUs are calling for a 5-6" liner and yours is 8"x8". If the conversion to gas causes condensation in the chimney, you might want to consider relining with stainless steel and at minimum have a chimney inspection done annually to make sure the tiles aren't deteriorating.

    If the HVAC technician would like to speak with me, please have him call my office."
    Western Mass Steam Homeowner
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