Why do my steam main vents keep releasing wet steam??

ccordero

I’m at my wits end.  I’ve spent so much money on new Gorton #1s from the advice of people here and elsewhere. Even some folks at the plumbing supply store where I bought them were telling me that Gorton was (is?) top of the line.

https://imgur.com/a/8Qhi4yX

See above picture of the current set up on my problematic main. I’m holding up the two other Gortons that I removed because they were releasing steam and failing to close. (The random non-Gorton one on the right was just one that I had sitting around that seems to be able to hold the steam in, but is a bit undersized).  But now the left one is acting up too; it’s failing to close and hold the steam in.

My understanding is that once this starts happening, there’s nothing i can do, the vent is ruined and I have to buy another. I’ve bought so many, enough to believe that I’m not just getting unlucky with defective parts.  There’s gotta be another explanation, right?  Does anyone have any ideas?

I’ve checked the pressuretrol: it’s a little below 1.5 psi right now. Doesn’t really ever get much more than that.  Water level also seems to be just fine too. Had a plumber come thru months ago who marked on the glass where the water should be.

Btw as a side question just cuz there’s a cold snap happening across the US right now and I don’t want to turn off the heat: is there any danger of leaving the heat on despite this vent releasing steam? I think there will be water loss, but my boiler has one of those automatic feeders that turn on when the low water cutoff is triggered.

jhewings

If your pressuretrol is set for 1.5, if the differential is 1, then even if the pressuretrol is accurate, your pressure will reach 2.5 psi (assuming additive). If the differential is higher than 1, pressure will be higher. If the pressuretrol is not accurate, pressure could be higher. For starters, set the pressuretrol to 0.5 psi and differential to 1. Make sure the pigtail is clear. You could consider adding a 0-3 psi gauge to know what your pressure really is (because the 0-30 gauge is not reliable). If you find your pressuretrol is not accurate and your pressure is too high ( above 2 psi), consider adding a vaporstat.

Long Beach Ed

You could have wet steam due to piping, water or boiler inadequacies. If there's a torrent of water vapor in the vent, particularly a Gorton vent, it won't be hot enough to close. You may find a Hoffman vent to behave differently in this application.

Big Ed_4

Everyone removes the supply pipe insulation because it was made with the bad stuff , but nobody replaces the insulation with not so bad stuff . The insulation is needed to deliver dry steam to the radiators . Insulate the supply piping and watch the system settle down .

BobC

Are the radiator vents hissing loudly? What does your pressure gauge read and be aware it could be lying to you. If the pigtail under the pressuretrol is gunked up it may not be "seeing" the real boiler pressure. Is the gauge being fed off that same pigtail?

There have been reports of bad Gorton vents, you can return those for new ones Make sure the boiler pressure is what you think it is.

Bob

ccordero

BobC said:

Are the radiator vents hissing loudly? What does your pressure gauge read and be aware it could be lying to you.

They’re hissing gently but constantly. Not too loud. Putting my hand in front of it and the gas coming out of it is hot. Shining a flashlight at it looks like steam to me. Pressure gauge reads 1 to 1.5 when it starts hissing but eventually reaches 2.

I haven’t a clue about the pigtail thing, a plumbing company installed it. Is messing with the internals of the gauge something I can do as a homeowner?

Alexnyu10

As others have mentioned, lowering your pressure max to .5 with a differential of 1 should help. Your boiler needs to have a cue to shut off once it’s already got that much steam in the system. I have the same exact issue as you with my boiler and the main vent leaking steam and then auto feed needing to regularly add water. This only occurs if my boiler runs consistently for 25+ minutes because the thermostat is telling it to, which only rarely happens (like in this ultra cold weather we are experiencing it does occasionally). After about 25 minutes I can clearly hear the steam leaking from the main vent until something turns the boiler off (options being the thermostat, the pressuretrol, or the auto water feeder). To make matters more complicated for me, I can’t even visibly access my main vents because they are insulated and also built into the ceiling of basement, I have no idea what former owners were thinking, so I can’t do a permanent solution until I save up to get it all ripped open to access. 

the temporary solution I’ve found from this group is lowering the pressuretrol setting to its lowest option .5 (gently counter clockwise on screw on top) and moving the dial inside to 1 facing you. Now my boiler knows to turn off just as it’s building up enough pressure for the main to leak steam. Also if the main does leak, it won’t be for long because eventually the auto feed water level will turn off the boiler to add more water. Get this inspected yearly by a good plumber to make sure it’s working properly. Here’s a good article on it that is a little less scary than what folks here will tell you- https://www.xylem.com/en-us/brands/bell-gossett/bg-steam-team-home/how-much-water-should-a-steam-heating-system-need/

One other thing, I have found that keeping my thermostat set at one temperature 24/7 also reduces this problem, because the boiler doesn’t get told by the thermostat to run for as long to try and catch up to a scheduled temperature increase. 

Hope some of this is helpful from a non expert, and this group is an incredible resource (just the group is a bit anxious about the auto feeder lol)