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.

What can I safely fire this boiler at?

Or how low can I go? I haven't calculated the EDR yet, I will, but it's to big judging by what I saw of the rads.

I went there on a no heat call. Thoroughly cleaned it and hauled a dumptruck load of debris out of the combustion chamber. And yes, someone had been charging them for a service every year. The flame had to burn up hill. The cone or ring that is tack welded on the end of the air tube assembly had since fallen off and was mired in the landfill in the bottom of the combustion chamber, leaving the flame to just kind of spread it's wings. I took it the welding shop and had it repaired and got it working like new. The transformer was bad which is what prompted the no heat call. Lucky, cause now we can get the rest of the system in shape. So anyway, I got the boiler fired up and then the vents all started whistling Dixie. They didn't stop either. They have a whole house humidifier. The wet return didn't warm up either. :s

I started asking questions.

Apparently at one time they had bad hammering going on in the pipes. Then it just kind of fixed itself.... Now they are adding water once a week :o They think this is normal.

I'm thinking the return is clogged as can be and all the vents have since been destroyed, spitting out water and steam, keeping the house warm and sultry. The PRV also sits atop the boiler dribbling a bit of water and wisping some steam like a cobra waiting to strike. I left the basement door open when I was in there.

I have quite a bucket list of repairs to be made. I'm not giving them a choice in the matter either.


  • wogpa67
    wogpa67 Member Posts: 238
    I would call both carlin and smith on that. It says 1.4gph as low fire but at what pump pressure? And then what nozzle would that be according to smith and/or carlin? Too many variables.
  • Larry_52
    Larry_52 Member Posts: 182
    edited February 2015
    Based on low stack temp maintenance issues keep down firing until the exhaust exit temp is 350 (with boiler at saturation) and call it a day if you still have adequate steam.

    The burner turndown is not the issue as it will drop below the boilers input requirement for load.
    EBEBRATT-Ed Member Posts: 13,454
    I believe Larry is correct. The old rule of thumb was to stay at least 100 deg over your steam or water temp to prevent condensation so the 350 he mentions is right
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,225
    Thanks guys.
  • icesailor
    icesailor Member Posts: 7,265
    @Harvey Ramer:

    "" The cone or ring that is tack welded on the end of the air tube assembly had since fallen off and was mired in the landfill in the bottom of the combustion chamber, leaving the flame to just kind of spread it's wings. I took it the welding shop and had it repaired and got it working like new. ""

    Whatever that boiler is, Carlin has the spec's on their web site as to what you need. As far as the repair done on the tube, all the welding done for the burner tube assembly is done on exact jigs. I doubt seriously that any welder can duplicate in the field what is done on a manufacturing jig. If the owner is in for the long haul, Carlin sells complete burner tube assemblies of the correct length for stupid money. Brand new. If the end cone burned off, and someone tries to repair it, it can be off by amounts you can not see and never run properly.

    If your goal is to play with the firing rates, EZ-1's use a spacing plate, matched to the firing rate, but I'm not sure if a 99FRD uses a plate or markings on the side of the burner. The Smith or Carlin I/O manual should tell you. Because it is a adjustable head burner, you don't need anything else to downfire it to its rated firing rate range. Unlike fixed head burners where you might need different air baffles.

    FWIW, you really should replace the whole tube assembly. Carlin will fix you up with the correct one for that particular Smith boiler.
  • Ironman
    Ironman Member Posts: 7,119
    Just wondering, if that boiler's approaching thirty years and has that many problems, and the returns are plugged, maybe replacement would be a better option? How much life could be left if excessive make up water is being added?

    Just asking.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,225
    While I agree, the boiler should be replaced along with a bunch of new piping work, the homeowner won't go for that since they are planning on building a new house within the next year or so. My main focus here is to get things operating safely so they can stay warm till their new house is ready. I believe the current house may be torn down after they move out.

    The tack weld spots were still on the end of the air tube. The welder did a perfect job on the repair. They needed heat right away. I couldn't be waiting 5 days on parts.
  • vaporvac
    vaporvac Member Posts: 1,520
    I hope for the new house they're going with GG's mini-tube steam system! :)
    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
  • wogpa67
    wogpa67 Member Posts: 238
    edited March 2015
    I took this out had it welded and ordered a new blast tube.
    The people they let drive fork
  • wogpa67
    wogpa67 Member Posts: 238
  • Abracadabra
    Abracadabra Member Posts: 1,948
    Looks like a PowerFlame burner? I must be blind cause I can't seem to find the damage from the fork lift.
  • wogpa67
    wogpa67 Member Posts: 238
    where the paint is gone on the weld would heat most homes.