New old radiator steam vent hissing

Giovanni722

hi again, I just had a new old radiator installed on my first floor and the steam vent (purchased from Home Depot for $15) is hissiny uncontrollably with no signs of stopping. Do you guys think it’s the vent? Do I just need to get a new better one? Is there something wrong with the radiator? Is there too much pressure? By the way this is a single pipe system! Thanks!

delcrossv

Yep. Do NOT buy vents from Home Depot.

Go to supplyhouse.com.

bburd

Home Depot does not sell decent steam air vents. However, there may be more going on. What pressure do you see on your boiler gauge while this is happening? Can you post a photo of the pressure gauge and the pressuretrol, which is the square gray box on the boiler wired into the other electrical parts there.

Giovanni722

I had a professional come over and do the required maintenance on my boiler and he said everything looked good. It’s a 1700 square foot house and none of my other radiators hiss like the way this one did tonight (again newly installed)

Giovanni722

@bburd

Jamie Hall

It's the vent. Get a good one… it'll cost more, but you get what you pay for.

Giovanni722

thanks @Jamie Hall, yeah makes sense. I was in a pinch and at Home Depot so I just picked one of those up hoping for the best.

bburd

I agree regarding the vent quality, but that pressuretrol is set a little bit high. You want a maximum of 2 psi cutout, and 1.5 is better. Try adjusting the main scale down just below 2 psi. Don't adjust it so low that the mechanism comes apart. The differential is set correctly.

Giovanni722

I have 9 radiators in the house and 2 are slightly bigger (living room and dining room). What would lowering it to under 2 do for me? Sorry first time I’m using this kind of system and the guy that was just here said it was ok so a little weary about touching those controls. Thanks! @bburd

bburd

The general rule for low pressure steam heating systems is to keep them under 2 psig. Pressures above 3 psig can damage vents, increase noise and at higher levels cause all kinds of other problems.

That said, if the current settings were working well until you changed that one vent, there is probably no need to change them.

Giovanni722

now that you say that a few radiators do hiss, I may knock it down to 2psi, it’s as simple as lowering down that lever on the right? Right? Just trying to make sure the boiler running as efficient as possible while also keeping noise and clanging down! I appreciate the responses! @bburd

bburd

Yes, the lever on the right. I believe it's controlled by a screw on top.

Giovanni722

just changed the valve and pressuretrol, here goes nothing!