Radiator Air Vent(s) Gurgling & Spitting - #2

FXProglJr

I had a problem with steam radiator air vents gurgling and spitting out water and steam that seems to be solved - see my other discussion with the same title - but now I have another question for all of you.

It seemed that I could replace an air valve and it would work fine. But in just a day or two, it would fail - once one got stuck closed and would not open, but several failed open or partially open so they would let steam out and spit water - not a lot, but enough to leave a small puddle on the floor. And this only happened on the two radiators on the second floor that had Danfoss thermostatic valves on them.

Out of curiosity, I cut open one of the vents that failed - see attached photos

Does anyone have any idea what seems to be fouling the pin? And why only in these 2 rads? What should I look for? and what can I do about it?

thanks

Fred

Where did you get those vents? Are they the cheap ones from the big box store? Get some good quality steam vents, Hoffman, Vent-rite, Gorton.

EBEBRATT-Ed

HAHA @Fred your not thinking China brass are you?????

Fred

EBEBRATT-Ed said:

HAHA @Fred your not thinking China brass are you?????

Yes I am! I see USAV on the side of the vent. That's the cheeap Home Depot, Chinese vent that isn't worth a quarter.

FXProglJr

well....let's see....the first ones I had were the ones I bought online when I bought the Danfoss thermostatic vents. They came in a box marked Danfoss - see photo. I also tried the Home Depot ones that look the same as the Danfoss (this is the one in the photo above), some Maid-O-Mist (angle w/ an elbow), a Vari-Valve (straight and set to the minimum) and a Gorton straight No. 5. The Vari-Valve (set at the minimum worked pretty good, But Gorton No. 4's seem to have solved the problem.

I'm still wondering what it is that fouled the needle and why is seems to have stopped with the Gorton No 4's

Abracadabra

FXProglJr said:

I'm still wondering what it is that fouled the needle and why is seems to have stopped with the Gorton No 4's

My guess is crappy material in the manufacturing of the vent or poor quality control. Either way, those vents are crap.

FXProglJr

from all those different manufacturers?

nicholas bonham-carter

If the main, (not rad) venting is inadequate, more air will be pushed out through the radiators from the mains. That air, maybe accelerated by over pressure can contain a lot of watery debris, which can contaminate the needle and seat of the radiator vent, causing it not to seal.
The cure is to check the pressure, and the main venting. During the venting phase, two ounces should show on your low pressure gauge.--NBC

FXProglJr

a few years back after I started looking and this site (and , if I remember correctly, in response to a comment from you, NBC), I increased the venting on both ends on my main (the furnace is in the middle of the basement and mains go out in both directions), but I'll check them. The pressure stays low until vents start to close and never gets any higher than 1-1/2 lbs

nicholas bonham-carter

To give you an idea of what venting can do, I have 6 dry returns with 3 gorton #2's on each. 1,000,000 BTU's, and 55 radiators.
It's rare that i see more than 2 ounces, in the venting, (air removal) phase. As steam finally gets to the rads, then at sub zero temps I may see 8 ounces.
This is to balance the aggregate venting capacity of the main venting against the total of radiator venting, so that the main venting will provide less resistance, and fill the pipes first before any of the rads.--NBC

Fred

@FXProglJr , to answer your question, all of those radiator vents have a float type mechanism in them. The Gorton's use a bi-metal element to open and close the vent. That bi-metal will expand and contract so I would expect that push/pull to be much more intense than a float that may well hang up in the orifice or, with enough deposits on the float/needle, may even be weighed down enough to not be able to lift and/or completely close. There appears to be a lot of deposits on those internal parts. I would check your water quality/hardness and use something to adjust the water quality, if needed.
Also, make sure the pigtail, that your Pressuretrol is mounted on is not clogged. That will allow your boiler to build more pressure than maybe you suspect, but I'm guessing water quality is the culprit here (aside from those cheap/disfunctional USAV vents).

Sailah

Sometimes when USAV you SPEND