leaking valve

starlogic

i got a old steam heating system that usually need to refill the water every 7-10 days. but this year i need to refill it almost every day and i found a valve is leaking when i refill the water and when the heat is running.
also seems i could never top up the water.

im guessing the leaking is causing the problem here.
wonder if this is a DIY thing that i could get it fixed by replacing this guy(see attached - what's this called?)
or i should look for a professional plumber?

the valve looks like this

JUGHNE

That is an air vent for the main steam supply line.
It looks to be on the end of a dry return near the boiler.
It should not pass steam or water.....only air and then close when the steam gets to that point.

And it also looks too small for the job.
Do you have any other air vents in the basement that resemble this?

You could replace this probably yourself...with boiler off.

starlogic

im guessing this is from the return line. it goes from top to the very bottom of the boiler.

i found another one looks exactly like this one.

Jamie Hall

That second one is a radiator vent. And should be used only on a radiator.

You can replace the leaker yourself, probably. The question is -- with what? How long and how big around are the steam mains and returns leading to that thing? If you tell us that, we can probably figure out what should be on there...

nicholas bonham-carter

If more than one vent is leaking, I would suspect the pressure has gone too high.
Check the pigtail under the pressuretrol for clogs.—NBC

starlogic

this is interesting. the second one pop out from a pipe like the one i shown in OP.

the left end of the leaking valve is from somewhere hidden in the ceiling and the bottom goes back to the very bottom of the boiler. that's about 6ft there.

JUGHNE

So you have 2 leaking air vents in the basement?
One in the first picture is an easy fix.
If the second one is above a ceiling, you can cut the ceiling open now or wait until it falls down.
If you wait to fix both, you are reducing the life of the boiler and the fresh water will rust a hole in the cast iron...time for a new boiler.

How about more pictures of the other leaking valve and also some of the boiler showing the piping floor to ceiling.
If you have any return pipes under the floor coming up at the boiler these are also likely suspects for leaking water.

If the vent leaks are repaired and water is still lost it has to go somewhere.

starlogic

thanks for all the helps!

i ended up getting a pro to fix it. i just afraid thing will get worse

neilc

did the pro, or you, check the boiler pressure, and or pigtail?
If it's high, like NBC suggests, you may be replacing vents again soon.