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Auto Water Feed Help

csrice Member Posts: 3
Hello good folks of Heating Help,

I recently purchased a house that has an oil fed steam boiler (pic of boiler system attached). Everything works great, except the auto water feeder (Mcdonnell-Miller model WFE-24). When the boiler is running, everything works as expected. If the water level goes too low, the auto water feed will add enough water and then stop. But, when the boiler is idle, the auto water feed will continuously add water until it floods. I find it odd that when the boiler is on, it works fine and doesn't flood itself. I suspect it's either the LWCO or auto water feed. I checked the auto water feed and see that it's set to the default dwell/feed setting, which is appropriate for my house (WFE-24 manual). I flush out the LWCO, which only has minimal sentiment. By no means am I an expert on steam boiler systems, does the community have any ideas on what I should troubleshoot?

Boiler system:


  • neilc
    neilc Member Posts: 2,707
    Let's start by dialing down your pressure setting.
    The grey box, your pressuretrol, the screw on the top, dial it down, counterclockwise, so the scale reads at its bottom, 0.5.
    Then inside, screw bottom front, there's a white or grey wheel, set it to 1.
    It may be with the pressure up high that your forcing water out of the boiler into the returns, and the flooding is the water returning.
    Set that pressure as low as it can go, 0.5 on that scale.
    Do you see your pressure gage move at all when the boiler runs?
    Asking cause the pigtail, the looped pipe under the Ptrol, does sometimes clog and need to be cleaned.
    known to beat dead horses
  • Fred
    Fred Member Posts: 8,542
    Have you ever cleaned the WFE-24 and replaced the strainer in it? It could be so clogged that it is not letting the internal valve seat properly.