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Oil Company Says I Need A New Boiler???

ktccapo Member Posts: 35
My heating arrangement is a two-zone hot water system fed by a 24 year-old Ultimate oil-fired boiler.

The previous (and original) owner of my home maintained the system well; it's provided five years of uninterrupted service since I purchased the home. I have a service contract with the local oil company, which provides a yearly cleaning/tune-up. I've done some basic stuff on it myself, like install a new aquastat, and run new lines to the oil tank.

After the most recent tune-up, and firing the boiler for the first time in late summer/early fall, I began to hear a loud, metallic banging noise coming from inside the boiler. The noise could be heard throughout most of the rooms in my home, as it reverberated through the pipes.

It seemed to appear when the boiler first fired, would last a few minutes, and then stop once the boiler reached operating temp, only to be heard again whenever the call for heat would be satisfied (like a car or truck engine "dieseling" after you shut it off).

I've had a tech come out it look at it three separate times; they installed a new high-hat vent, bled all the baseboards, made sure the cut in/off temps were set correctly, added some cleaner to flush out sediments, and drained the boiler down to add fresh water.

The noise intensified somewhat after the flush, in that it sounds "clunkier" and less metallic than previously.

Despite the noise, the system is still supplying heat to all of the baseboards on both zones.

I'm stumped, and so appears to be the oil co, as they say there's nothing left for them to do, other than install a new boiler.

Could the boiler in fact be damaged beyond repair, or is this just a case of the oil co not wanting to run up the "free labor" of my service contract on something they can't figure out? Is there something they're missing?

Any advice would be much appreciated. Many thanks and best,



  • Zman
    Zman Member Posts: 7,447
    If you post a video recording with audio, I bet someone on here can figure it out.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • That kind of sound is characteristic for an unhappy heat exchanger generating too much heat. If the water isn't moving fast enough through the heat exchanger, the water will flash to steam and will make the sound you describe.

    Could be a pump problem, could be an air problem; could be something else. But it's something an experienced boiler-whisperer would have to pay you a visit to solve.

    Where in the country are you?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hourTwo btu/ per sq ft for degree difference for a slab
  • lchmb
    lchmb Member Posts: 2,997
    make sure the probe on the new aquastat is fully inserted in the well. And I would add a bottle of 8 way boiler treatment to see if it's a sediment issue.. but a video would help
    HVACNUT Member Posts: 5,032
    ^^^ yes, video and pics will help.
    Is the Ultimate a Dunkirk?
    Cast iron or steel?
    Is it possible the noise is from the weight in the flo valve. Not seated correctly, it will make a metal on metal clanking.
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,132
    +1 to @HVACNUT I'd get someone else in there that has a little more experience.
  • Steamhead
    Steamhead Member Posts: 15,997

    +1 to @HVACNUT I'd get someone else in there that has a little more experience.

    This. Where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    EBEBRATT-Ed Member Posts: 13,454
    We had a similar situation with banging pipes. The techs that went replaced everything.........parts changers.....except what needed to be checked....the expansion tank was shot and the water feeder piped incorrectley
  • ktccapo
    ktccapo Member Posts: 35
    Many thanks for all of your replies, much appreciated. I'm located up in the mountains of Vermont, where you'd expect there'd be a bunch of "boiler-whisperer's running around," but not so much. As per some of your suggestions, I've attached photos of my set up; I am uploading to Youtube a short video from the the backside of the boiler featuring the noise in question, and will post the link shortly. Please let me know if what you think, and thanks again!

  • ktccapo
    ktccapo Member Posts: 35
    Here's a link to the video of the banging noise:

  • pecmsg
    pecmsg Member Posts: 3,889
    Give Jerrys kids a call, Jerry retired a long time ago.