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Leaky fill valve story.

brandonf Member Posts: 205
Quick story. 

Fired up my extremely oversized and incorrectly installed steam boiler for the season. 

Ran for about 20 minutes and all seemed good. 
Sight glass was filthy but looked like it was at the right level. 

Got ridiculous water hammer on all risers. 
Boiler shuts off and does not restart. 
I didn't feel like dealing with it.
Had the landlord call the plumber. 
Next day the plumber says the boiler was overfilled.
The mains were full of water. 
And plenty of gunk clogged the pigtail.
He mistakenly assumed that I had overfilled it because I couldn't see the sight glass clearly. 
He drained it and cleaned the glass and said I was all set. 
And a few days later I thought about it and realized that the fill valve must have been leaking water into the boiler. 
So I go back downstairs after a few days and lo and behold I have water starting to leak out of my main vent. 
I drain a few gallons back out to the proper level. 
And I changed the ball valve. 

(No automatic water filler on the system)

Thank God all the radiators are on the second floor or else I would have been having wet floors within the next few days...

I am forever grateful for this site for all the knowledge it has given me. And peace of mind as well. 
Happy Thanksgiving

Homeowner, Entrepreneur, Mechanic, Electrician,

"The toes you step on today are connected to the butt you'll have to kiss tomorrow". ---Vincent "Buddy" Cianci


  • ethicalpaul
    ethicalpaul Member Posts: 5,702
    Your landlord should be paying you, not the other guy
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    @brandonf, Is the fill line connected to the hot water supply or the cold water supply? The reason I ask is that some people think it's a good idea to use hot water to fill/top up a boiler because the water is pre-heated, but this invariably leads to heartache because water heaters cause minerals to precipitate, and sooner or later you get chunks of scale in the fill valve and it leaks water into the boiler.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24