Main Vent Recommendation

MikeC_3 · February 18

On the advice of forum members in response to my previous post regarding trying to balance the temperature between floors in my mother's 3 story circa 1900 Victorian house, I located the main vent that is hidden in a corner along the ceiling in the basement. The 4 year old system is single pipe, one zone steam.

From what have I researched, the installed valve is without a doubt, incorrect. After reading through many threads, I am amazed that the system has worked as well as it has for the 30+ years I believe that it has been installed for. Obviously, it now shows signs of failure.

I am going to replace it and the two most recommended options seem to be the Gorton # 2 and Jones "Big Mouth". Should I look for anything specific? Are either acceptable? It looks like I should just be able to unscrew the white elbow from the main and install the vertical vent.

Any idea what the current valve is rated for? What differences should I notice once the new one is installed - except for more even temperatures (hopefully)?

Thanks again!

ethicalpaul · February 18

Don’t worry about the existing vent—it’s not enough.

I don’t know the volume of your main but I greatly prefer the Gorton #2 to the Big Mouth.

You may have top clearance issues regardless and that tapping location isn’t optimal on the side of the main

MikeC_3 · February 18

Thank you.

I have 9 inches from the top of the elbow to the ceiling. The # 2 looks to be 6.5". Does in need more space than that?

ethicalpaul · February 18

https://forum.heatinghelp.com/discussion/comment/1888567#Comment_1888567

Not in my opinion. I can't tell the sizes of your fittings there…it looks like it may be a 1/4" to a 1/8"…the Gorton #2 has a 1/2" male fitting on it so you might need some adaptation there.

It's kind of difficult to tell the layout of your main there from the photos…is this area near an end-of-main drip to a wet return? Is that

MikeC_3 · February 18

Yes, that's a 1/4" to 1/8" fitting.

The vent is about 15 feet from the boiler where the main bends towards the front of the house. I attached a photo notating the main - that is not the location of the vent.

dabrakeman · February 18

So that vent currently is at the end of the main after the last radiator runout? The pipe continuing on in the photo after the drop is condensate return only going back to the boiler? Is this the only main or do you have two (looks like you have two…). IF there are two is there another vent somewhere? Would like to know what the total length and pipe size of the main/s being vented are. My apologies if you already posted more detail or other pictures in a previous post.

I'd have your new vent right up nearly to the ceiling but I just wanted to verify from the sizing of the pipes whether a single vent is enough.

bburd · February 18

The Gorton will close against water. The big mouth will not. Since the vent is tapped off the side of the main, water is a concern so I would not use the big mouth in this case.

ethicalpaul · February 18

That main looks like a rather small pipe size…is it a main with just a few radiators on it, or even just one? If so, or if it's very short a Gorton #1 might be worth a try to start with.

MikeC_3 · February 18

Apologies, the vent is off the pipe that is at 12 o'clock at the photo.

There is only the one vent that I attached in my initial post.

The current setup worked fine - as in all the floors heated quickly and evenly until this past year - for over 30 years. Probably not efficiency-wise. The previous boiler lasted more than 25 years until it developed a crack. This one was installed 4 years ago. I had a thermostat issue last year that was causing a short cycling issue. Resolved that, and then had a clogged pigtail earlier this year. When that was fixed, the temperature difference between the first and second/third flors was over 12 degrees. Managed to lessen that by correctly setting the installer options on the thermostat that the technician failed to do.

It is currently about 6 degrees hotter on the upper floors. Researched further on this forum, and everyone pointed to the main vent. Located the vent that I included in my initial post - which obviously looks like the culprit.

My thinking is that if I replace it with a somewhat more adequate vent, the difference with lessen even further.

I would love to balance the system in the near future but for now just trying to make the house comfortable.

MikeC_3 · February 18

The main is 4 inches. It has 17 radiators attached two it.

Captain Who · February 18

The vent looks like something that someone installed as an afterthought rather than the original vent. It should have been on a 45 higher up on that elbow at the very least. I am still confused as to whether this vent is at the end of the main after all the radiator takeoffs or not. It doesn't look that way in the photo.

It has writing on it, if you're interested. Maybe Hoffman Specialties? Probably has a model #. I know it is probably irrelevant because it may be undersized but it might be interesting to know.

You say the boiler installation was done four years ago. It worked fine after that? It looks like they did a bullhead Tee new header that goes into an older header. That isn't proper, which is why I'm wondering.

MikeC_3 · February 18

It looks to be right smack in the middle. It is about fifteen feet from the boiler on the pipe that is in the center of the attached photo.

If I had to guess, the system never had a vent. Then, when the converted coal to gas boiler was replaced in the 90's, I assume this vent was added - most likely as an afterthought and where it was somewhat convenient. I can make no claims regarding the efficiency of the system, but the house has aways been at a reasonably consistent temperature on all floors until now.

ethicalpaul · February 18

https://forum.heatinghelp.com/discussion/comment/1888578#Comment_1888578

hmm, the one with the arrow pointing to it in your photo is the one on the right in this zoomed-in image of that photo (I think)…it is 4"?? Could be the photo is fooling me. But anyway if it is that large then don't bother trying anything smaller than a #2 I guess.

MikeC_3 · February 18

Sorry, as I previously mentioned - I labeled the wrong pipe. The main is the larger one in the center of the photo.

Captain Who · February 18

It had to have a vent for each main, coal fired boiler or not. Even if it was a vacuum system, they would've had vacuum style vents. And they totally need to be at the end before the drip, or if you had dry returns they could've put them at the end of those dry returns.