What is the life Expectancy of a Wood Boiler?

henfruit Posted By henfruit, Oct 26, 2012 at 8:16 PM

  1. henfruit

    Minister of Fire

    Nov 27, 2007
    New Hampshire-Maine border
    I recived a call from a women saying that her wood boiler had sprung a leak and flooded the cellar.To make a long story short, she had a 1979 tarm combo that she had bought used 2 years ago.It was time for a new boiler.I think for 33 years the boiler had done it's job and it was time to be shipped to China to be sent back to us in some other form.
  2. BoilerBob


    Jan 14, 2011
    SW Nova
    Hmmm?? Mine is 1976 HS Tarm with no boiler protection, maybe time to plan for replacement.
    The steel must be getting thin in some places. It works so good, I hate to part with it yet. Until it springs a leak that is...
  3. heaterman

    Minister of Fire

    Oct 16, 2007
    Falmouth, Michigan
    Unless I was absolutely certain of the maintenance given to the boiler and the control strategy used to protect it, I wouldn't touch one over 15 years old. I have to question the rationale of purchasing a boiler of that age and then investing $$.$$ into the installation of it. :eek:
  4. Gasifier

    Minister of Fire

    Apr 25, 2011
    St. Lawrence River Valley, N.Y.
    When I bought my house it had the original oil boiler that was installed in 1978. I bought the place in 1994. So 16 years then. I used that same boiler for another 8 or 9 years after that. So a total of about 24-25 years. And it was still working. It had no boiler protection. Who has the oldest wood boiler in the boiler room?
  5. heaterman

    Minister of Fire

    Oct 16, 2007
    Falmouth, Michigan
    I don't own a wood boiler myself but I service a Tarm dual fuel oil/wood that was installed in 77or 78. Service means, tune up the oil burner, clean the flues, inspect chimney, test water quality (lab) .

    FWIW ..........I serviced a wood/coal forced air furnace last week that has a patent date on the cast iron door of 1911. It was converted to natural gas in the early 50's when a gas field was opened on the property. It's been burning field gas since then. Has to be some kind of record.
    Gasifier likes this.
  6. maple1

    Minister of Fire

    Sep 15, 2011
    Nova Scotia
    Is there really a need or advantage to testing water with a closed pressurized system? How much, aside from cleaning ashes out & making sure your boiler return temp is where it is supposed to be, is there to do to maintain a wood boiler to get longer life out of it?
  7. Bob Rohr

    Bob Rohr
    Minister of Fire

    Jan 9, 2008
    SW Missouri

    It depends on what fluid you put in the system to begin with and how well it was cleaned and flushed out.

    If the system has a lot of copper that was soldered you should flush out the flux residue or it will taint the water. Oils and pipe dope, assembly fluids and greases should all be flushed out. It's a good idea to use a hydronic cleaner, at least some TSP or dishwasher soap to cut the oil and grease, flux etc.

    If the system was cleaned and good quality water added, no leaks, then the fluid should be safe for many years.

    Avoid water that is hard, high TDS, high chlorides. Many boiler manufacturers now indicate the water quality and levels for those.

    Keeping O2 out of the system is very important. Always use a barrier pex on hydronic system. We are still dealing with the early PB, and non barrier rubber tube systems that sludge up and destroy non ferrous components.

    The type of test and readings you get depend on what is in the system to begin with. Hydronic glycols will be in the 10- 11 ph range. If the drop to the 7 range it's time to replace them or re-buffer them. Different hydronic conditioners will have specific test kits to assure that they are still in good condition.

    I'd stay away from hard water over 10- 12 grains, it will precipitate out the hardness on your boiler surfaces and need an aggressive chemical to clean. This is the same as with instantanous type water heaters, with new water added daily the hardness will coat the HX surfaces.

    Ideally the system would be filled with DI or DM deionized or demineralized water. You can rent the equipment to attach to your water supply to filter you boiler fill water. It looks like a small water softener tank, but does not back wash. After so many gallons run through the tank is returned and re-bedded. Culligan has DI equipment available if you have a large system to fill. I take a 55 gallon plastic barrel to their location and they fill it with DI water for me. It's cheap insurance if your jobsite water is hard, rusty, sulphery, cloudy, etc.

    Chemicals can be added to correct bad fill water, but it's best to start with good fill water. A simple ph strip or pencil tester is a good tool to check fluid conditions.

    A slide from a recent water quality seminar presented by GEO installer and troubleshooter Jeff Persons in Ohio, used by permission

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