Help! Water spewing out of radiator air valves

dvinarc

A little back story, I moved into my Grandfather's house that has been vacant for about a year or two 3 months ago and have been dealing with various issues around the house such as putting in new water lines to kitchen, replacing fallen plaster ceiling, etc.

Now that the temperature has been dropping at night I turned on the heat which is a boiler run one pipe steam radiator system. I went into my bedroom maybe a few minutes after running the system and found water spewing out of the radiator air valve. So no problem I thought, I cleaned up the mess, ran to HD bought a new air vent valve (#6 for my upstairs bedroom) and replaced it. Ok, turn on the heat again walk around the house and now the down stairs family room radiator is spewing out water. Turn off the heat, look at the air vent valve which looks newer and fine but isn't screwed in securely, so I wrap a little plumbers tape around the threading and screw it back in. I turn the heat back on walk around the house again and see the upstairs bathroom radiator is now spewing water out of the air valve! Each time it is about a gallon of water that is coming out. I'm not sure what is causing this. I had my boiler serviced a month or so ago and I know that water is always coming out of only 1 radiator out of 10 in the house at a time, and it is always from the air valve. Please provide any assistance if possible I have already racked up thousands of dollars of bills in the process of fixing previous problems around the house and while being laid off due too Covid I would really not like to call a plumber unless absolutely necessary. Thank you!

ethicalpaul

It’s not the vents’ fault  (although they may also need to be replaced but don’t buy the HD ones). They aren’t supposed to have to hold back water, only steam at low pressure below 2 PSI or so.

Sounds like something is causing boiler water to be thrown into the steam pipes.

it could be bad near-boiler piping or too high a water level or too much water treatment added to boiler or any combination of those.

can you post pics of the boiler from a reasonable distance showing floor to ceiling from several angles? then a more close shot of the controls and water level.

if you want to start learning get Dan’s book We Got Steam Heat or The Lost Art if you’re really serious: https://heatinghelp.com/store

Erin Holohan Haskell

@dvinarc, this article may help you troubleshoot: https://heatinghelp.com/systems-help-center/spitting-or-hissing-air-vents/

And as @ethicalpaul pointed out, this book will help you get a better understanding of the steam system: https://heatinghelp.com/store/detail/we-got-steam-heat-a-homeowners-guide-to-peaceful-coexistence

STEAM DOCTOR

Could be lots of causes. First off check the boiler water level. Post pics of boiler and boiler piping.  Go from there.