should i pressurise my OWB

kealo Posted By kealo, Oct 16, 2012 at 3:36 PM

  1. kealo

    Member 2.

    Sep 7, 2012
    Hey guys i have a wood doctor furnace that is open to the atmosphere. I was recently on there web site and they now only make pressurised boilers. claiming to last longer due to the ingestion of oxygen in an open system bla bla.. See link

    I know that pressurised system last longer and there is less to no corrosion.

    Do you think i should pressurise my system? at the top of the boiler there is a 1" open vent i was thinking of welding a coupling on and adding an air eliminator, pressure tank and relief valve. Is this all i would need to pressurise my system or am i missing something??

    thanks for your input
  2. maple1

    Minister of Fire 2.

    Sep 15, 2011
    Nova Scotia
    Not if it isn't designed to run under pressure, I wouldn't think. There's quite a difference in a pressure vessel and non. Also I've heard some bad stories about those - adding any pressure at all could reveal something real bad in a big hurry.
  3. Eric Johnson

    Eric Johnson
    Mod Emeritus 2.

    Nov 18, 2005
    Central NYS
    You get a certain amount of pressure in an unpressurized OWB and my impression is that the water does get un-oxygenated over time, so I don't think corrosion is necessarily a given. My folks have had the same Heatmor for at least 15 years with no problems. But as maple1 notes, if it's not designed to be a pressure vessel (and yours isn't), then don't pressurize it.
  4. raybonz

    Minister of Fire 2.

    Feb 5, 2008
    Carver, MA.
    Introducing "raw" make-up water into an oil boiler is the only time corrosion is introduced this is why they last for decades. Based on this an OWB would see the same effects plus you can also heat the pressurized water to a higher temp without boiling just like a car cooling system. I wouldn't pressurize a system not designed for this purpose as you could cause hazardous conditions and risk boiler failure unless the boiler maker warrants that it OK to do this..


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