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Boiler Blowdown & Chemical Cleaning Strategies

cubicacrescubicacres Member Posts: 300
We have a Weil Mclain EG75 for our single pipe steam boiler system, and were wondering if using the Steammaster tablets helps with the blow-down process to remove the sludge & keep the boiler clean. Has anyone used this product and do you know what it helps with other than the oxygen scavenging we read about to lower our corrosion over time? We're wondering if adding a King valve would be worth it to get some more psi in the near boiler piping with blow-downs, or if it might be too much trouble to add 5 years after our installation.


  • Jamie HallJamie Hall Member Posts: 12,847
    Some people do use steamaster -- in half or less of the quantity recommended. Some don't use much of anything, if anything. The less fresh water you can put in the boiler the better!

    On blowdowns. Is this a float type low water cut off you're blowing down? Should take no more than a gallon -- if that -- to clear it if you are doing it at least once a month (some say as often as once a week, but...). The boiler itself -- bottom drains -- shouldn't be blown down more than once a year -- if that -- and only if you really know that there is a lot of crud in there. In my opinion, anyway.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • cubicacrescubicacres Member Posts: 300
    edited May 26
    If I'm remembering correctly, we're using about 1/3 to1/2 the reccomendation for the steamaster tablets, 1 tablet max instead of the directions 2-3 tablets each time once during the season when the water fades to clear from violet & at shut-down for summer when we fill the boiler with water. We heard too much can cause foaming & water trouble in the boiler. Other than reducing dissolved oxygen to reduce corrosion, are you familiar with other features most chemical additives use to help with in steam systems, and why people like to use them at all? At first we didn't use any chemicals, then tried the steamaster when we thought we might not get all the leaks that seemed to re-appear periodically each year or two.

    We have a probe low water cutoff. We blow down the bottom drain on each side of the boiler (see above pics with small black/blue gate valves at bottom & small black gate valve at lower left condensate return) about twice a year to let half a gallon out until it runs clear (violet with steamaster), also at the condensate return the same amount & frequency. Wondering if there's other things we could do to keep our boiler clean. I think that larger valve handle on the condensate return to the right of the one we use to blow down would isolate the returns from the boiler & could be used with a king valve if we had one? The installer added it per our request, but not the King valve due to costs of $1,000+ which scared us away at the time.
  • ChrisJChrisJ Member Posts: 10,973
    Every 1-2 years I drain my boiler and rinse it out with a wand.
    I then toss in 2 new Steamaster tablets while refilling it.

    I can get away with 2 Steamaster tablets in an EG-40, no idea why.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
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