Old Vent Questions

Warsaw

Hi All - Last year we got a new boiler and ever since have been having issues with some rads not heating all the way (and other issues, but I'll start with this). Based on reading I have done in the forum and the <em>Lost Art</em> I am guessing that at least one of the problems is bad or clogged vents. So, a few questions...



First, all except one of the rads in the house has Hoffman 1As. Some of them, however, are shaped differently. These particular ones seem to be on the rads that don't heat properly. I know they are adjustable and I haven't focused on trying to balance the system yet, but these particular ones seem to be an older version of the 1A. Anyone know how old? How likely are they to still work? Is it worth cleaning them or should I just replace them?



Secondly, does anyone have any information on the Hoffman No. 6 vents for the mains? We have one main and the main vent appears to be a Hoffman 6 (see photo), but they don't seem to make them anymore. Any idea how old this might be? My sense from this forum is that with the new, modern boiler (it is physically much smaller than the old one) I need a bigger main vent. It is also clear that the contractor didn't so much as touch the old main vent, so who knows if it even works.



Here are photos of both. Any insight?



Thanks!

crash2009

I'll give ya $1.90 for the Hof 1

Here is an old catalogue that has your vents in it.  I'll give ya $1.90 for the Hof 1.  Its gota be shiny though.

http://www.heatinghelp.com/files/articles/1332/5.pdf

The Hof 6 has 3/8" threads

Rod

Old Vents

Hi- Radiator vents, over time, wear out. I read somewhere that the expected life of a radiator vent is 3 years. Some people have had luck boiling them in vinegar to clean them. According to Gerry Gill's excellent venting book, a Hoffman # 6 is an obsolete vacuum vent and it has a very small orifice. You'd be much better off to replace it with a Gorton #1 that has ten times the venting capacity. If you need Hoffman 1As or Gorton #1s, try Pex Supply on the internet.  Increasing your main venting capacity on each steam main should make a big difference.

- Rod

Warsaw

Thanks

That's what I suspected. Not surprising that the vents in this place were not properly maintained. Also, FYI I read the the Lost Art last night that Dan, at least, recommends changing all the rad vents with a new boiler, so there's my final answer right there.



Got the venting chart on the way, so we'll replace that main and get the system balanced soon (I hope)!



Thanks again!

crash2009

heads up

Changing the main vent is not going to be easy.  According to the booklet I sent you the hole its screwed into is 3/8".  Most of the new vents are 1/2 or 3/4.  Just a little heads up for ya.

Steamhead

I believe the #6 vent

is a vacuum type, which should be replaced. Measure the length and diameter of your steam main and we can tell you what to replace it with.



Is the other vent really a 1A, or a 2A? If the latter, it's also a vacuum type.

Warsaw

Main size

Thanks! It's a little hard to measure precisely, but I am assuming I only measure the large horizontal pipe and not the branches off of it. The closest I could get was 60.25 feet of horizontal - it is shaped in a spiral of sorts. The OD on that is 2.4", which looks to be 2" according to this chart: http://en.wikipedia.org/wiki/Nominal_Pipe_Size#NPS_.E2.85.9B_to_NPS_3.C2.BD



There is also the near boiler piping, which would add 3 feet of 3.5" pipe and roughly 7 feet of 2" pipe. Not sure is this is needed for the calculation or assumed.



I am attaching a photo of the boiler and the tapping for the main vent. It appears that the main vent is on a 3/8" tapping that goes up to 1/2" and then back to 3/8". Is this too small? Should I think of opening that up somehow? One more (well, two) question: the tapping is only about 2" from where the pipe bends down to become the return portion. I read in Dan's book that it should be about 15" from the elbow. Is this a big problem?



So the big question - I am just a handy homeowner. Is this too big a job to handle? Seem basically straightforward, but...



Thanks again!

Steamhead

Is there a bushing in the steam main

where the vent riser comes out of it? 

Warsaw

Bushing

I am not entirely sure what a bushing is in this context, but I think the answer is no. The 3/8 pipe connects directly to the main. the tapping is in a small section of pipe that sits between the elbow and a much larger section. You can see it pretty well in the photo.

Thanks!

Steamhead

Have the tapping enlarged to 1/2 inch

and a second 1/2" tapping made at least 4" from the original. Then install a Gorton #2 vent in each tapping. You won't believe the difference!

Warsaw

Tappings

Excellent! Do I still need to elevate them from the main? Thanks for the info - very, very helpful.