Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Advice HB Smith Boiler firebox replacement

maxnix Member Posts: 1
My yearly boiler service resulted in bad news. The technician said the firebox had crumbled. I need some help id-ing the boiler. Its an HB Smith and I think the model number is 110L but I cant find any info online about it.

I need to decide whether to have the firebox relined or replace the unit. It has worked well until now. My oil supplier is steering me to replace the whole boiler saying that we will recoup the cost with the greater efficiency. Also the hot water coil has some corrosion at the connections so that may be on its way out as well.

I looking for a sanity check about which direction I should take. Below are some images of the boiler.

Thanks for looking!
Max Ehrlich


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,023
    Try tech support at Lynn Products (781) 593-2500 [email protected]. If anyone can help you , they can
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    EBEBRATT-Ed Member Posts: 13,759
    Fix it.

    The 1100 series Boilers are good boilers. I would not give up on it just for a combustion chamber replacement.

    The problem is finding someone that will do it. Obviously, your oil company doesn't want to fix it they want to sell you a new boiler.

    So i would search around for someone. Check "find a contractor on this site" and post your location someone may know someone or have a recommendation.

    As far as the coil goes, I would take the connections apart and clean them up and reattach them. If need be that coil can be easily replaced but there is no need to do that unless the coil is leaking.
    HB Smit was the only boiler MFG to use bolts and nuts to attach the coil to the boiler (instead od threaded tapped holes)

    If possible post a few pictures of the combustion chamber.

    Your service tech may be crying wolf. If you look at the boiler name plate you have either a 4,5.6 or 7 section boiler. So the model # would be a 1100L-#of sections (either 4,5,6,7)-S (for steam)

    Now that I am thinking about it I am not sure the 1100 had a normal combustion chamber. I think it just has loose material on the floor of the chamber to insulate the floor and the sides of the mud leg.

    Unfortunately I threw out the gobs of HB Smith books I had. (they got wet and moldy in a flood) but will look on line
  • mattmia2
    mattmia2 Member Posts: 8,372
    That header is very wrong, but if it doesn't bang and heats evenly we'll ignore it.
  • jesmed1
    jesmed1 Member Posts: 95
    edited September 19
    " My oil supplier is steering me to replace the whole boiler saying that we will recoup the cost with the greater efficiency."

    LOL. When you see their price quote for a new boiler and do the math, you'll find that the maybe 5-10% efficiency improvement will result in a payback period of like 40 years. Find someone who will fix it.
    EBEBRATT-Ed Member Posts: 13,759

    To update my previous post. That boiler is an HB Smith Model 1100-#of sections-S (for steam)

    The dates to around 1970 give or take. The boiler was sold to be used on steam or hot water.

    To find the number of sections all you need is a measuring tape. The boiler is 23 5/16 wide.

    4 section is 19 3/4 long max firing rate on oil 1.30gph
    5 section is 24 1/4 long " " 1.65 gph
    6 section is 28 3/4 long " " 1.95 gph
    7 section is33 1/4 long " " 2.30 gph

    In any event the boiler has no combustion chamber as in a normal combustion chamber

    It is what Smith called their "low set" design where the mud legs of the boiler sit on a steel channel base that is about 1" high. That is what the "L" in the model numbers mean.

    With the advent of the forced draft high speed burners (Carlin 100crd, Beckett AF) around 1970 Smith took their 1100 boiler that did have a combustion chamber and a cast iron base and did away with the CI base and combustion chamber. This is because the newer high speed burners did not require a combustion chamber.

    The only thing required is to insulate the floor of the firebox and up the side of mud legs (the lower part of the boiler sections about 3".

    Now, if your oil company is telling you the "combustion chamber is crumbling" they don't know what they are doing.

    I do not know the name of the product that Smith used on the combustion chamber floor it used to come in burlap bags and it was a loose material and was just dumped on the floor of the fire box. Probably not available anymore. It may have some insulation under that material I don't remember.

    They used the same "Low set" design on the 2000L and 2500L boilers if anyone has tangled with those.

    If it had to be replaced, I would use regular 2 1/2 X 4 1/2 x9" insulating fire brick

    The other giveaway to what this boiler is is that the burner is mounted on an angled front plate with the burner tipped foreword slightly. This is to keep the flame from hitting the sections.