Hoffman 1A Vent Question

marcusjh

So - I have a radiator that's at the very end of the line (I think), and it's in my daughters room. By the time the steam gets to it, the pressure is so low, the Hoffman 1A won't let it in, even when it's wide open on the highest setting. Her room was freezing this morning, rest of the house was fine. A little while ago I removed the screw nut, and adjuster from the 1A, and it's now heating up.

I need to know whether the closing mechanism inside 1A also blocks the hole for the screw nut (I don't want her room filling with steam). Does anyone happen to know?

Thanks!


Marcus

LionA29

Take the valve off and adjust it and then tighten the screw. Sometimes the adjusting cap covers the vent hole which closes the valve.
If you say it heats up with screw and cap off, that's what is happening.
Make sure radiator is not hot ( filled with steam) when removing valve!

KC_Jones

What is your main venting like? You may be looking in the wrong place for a solution. If the rad is trying to vent some of the main pipe it will perform like this, or it could have a really long un-insulated run out to the radiator. Taking it off and getting heat just means at max the vent isn't capable of doing what is being asked of it, which points to my above comments. Let us know what else you have going on with the main and that rad run out.

marcusjh

Yea, I know all about that. The Hoffmans aren't made like they used to be (the metal adjustment doesn't fit snug enough). - I blew into it after I tightened down the nut to make sure it was all the way open.

Apparently both holes will vent steam, I just need to know whether both holes shut down when it heats up.

marcusjh

The main vents do heat up - they were installed in 73, or 74 when they put the additions on the house. I can take a photo if you want. I DO hear them hissing a bit when the furnace is running, so it sounds like they are venting -although, it looks like a funky set up, so I'll post some photos.

marcusjh

marcusjh

Comes out from the wall, goes down to a horizontal, then goes back UP to the rest of the house. The piping was reduced from one size, to another before it comes through the wall. I don't know why (before my time).

BobC

main vents that old could be partially blocked by mineral deposits and are probably too small, how long are the steam mains?

Bob

marcusjh

From the furnace, it's 45 feet to the main vents.

Fred

Is that 45 feet for each of three mains? One Barnes and Jones Bigmouth should do fine, on each main..

Abracadabra

You need better main venting. Those vents are no where close to enough.

marcusjh

It comes from the furnace 45 feet to the first main which comes through the wall (pictured), then goes down to that horizontal pipe, and then comes back up to the other mains, then wraps around to the other side of the house before it goes back to the furnace (so another 20-25 feet from the tallest main). All in all maybe 75 feet of piping that loops around the basement (not including the verticals).

Fred

I see three vents on three different pipes. Each of those look like dry returns at the end of three individual mains that drop down to a wet return.

marcusjh

And I think we have about 2500 sq.ft. First floor ceilings are 9ft. Upstairs is 7.

marcusjh

Sorry, I forget the terminology. Fred you're correct. They all converge to the wet return pipe that goes under the cement slab back to the boiler. The upstairs pipe (middle) goes beneath an unheated area (crawl space), and then goes to the second floor.

Fred

So is each 45 feet long or is one 454 feet long and two 25 feet long?
If each is 45 feet long, put a Bigmouth on each. If one is 45 feet long, use the Bigmouth on it and the Barnes and Jones Vari Vent on the shorter ones.
https://www.amazon.com/Barnes-Jones-Big-Mouth-Vent/dp/B01F26P13C/ref=sr_1_fkmr1_1?ie=UTF8&qid=1481928791&sr=8-1-fkmr1&keywords=Barnes+and+Jones+Bigmouth

https://www.amazon.com/Barnes-Jones-BJ-2VV-NPT-Vari-Vent/dp/B01GQP0DQ8/ref=sr_1_1?ie=UTF8&qid=1481928860&sr=8-1&keywords=Barnes+and+Jones+varivent

KC_Jones

Wait you have a horizontal pipe that goes down and then back up? If I am understanding that correctly you have a water trap and anything past that won't ever heat. Need more pictures of what you described to verify.

Edit: Also a picture of the pipe reduction, those can be a problem if not done correctly.

marcusjh

Pipe goes up off boiler, and goes in two directions, North & South. The South pipe runs about 45 feet around the basement to the vents. The North pipe runs about 35 feet to the vents.

Both North & South pipes converge down to a horizontal pipe which is about 2 feet off the floor. A third pipe runs up from that to another vent. I thought it went upstairs, it goes to the den instead.

Fred

The mains start right there at the boiler. When they go in each direction, horizontally, off of those risers above the header. That's where we need you to measure from, all the way to the vents.
The only other question is that third pipe. It can not provide steam. IT is a return from a third main or a branch off of one of the other two mains. It goes down from that third pipe (to carry condensate to the wet return (the pipe that is near the floor). Fol;low that pipe around the basement and see where it connects to one of the other two mains and measure that as well. It looks like it is only an 1.25 or 1.5" pipe, if that is it on the left of your last picture.

marcusjh

This is how far off the ground the horizontal pipe is (wasn't two feet, it's 16 inches).



Shot of the other side of the furnace.

Fred

Yes, that is a wet return that carries water from those three pipes back to the boiler, through that under ground pipe that comes up next to the boiler.

marcusjh

Ok - just to clarify - I Did measure the horizontal mains from the boiler (I didn't measure any verticals) - one pipe runs North (about 35 feet), the other runs South (approx. 45 feet). Off of those mains are the pipes going to the various radiators (one goes to the living room, two go to upstairs bedrooms, etc).

On the photo that shows the vents - the pipe that is coming through the wall is the north pipe, the one right next to it is the South pipe. Both turn 90 degrees downward to that horizontal pipe.... and I am now confused about that third pipe (the one with the long vertical vent), and why it would even Have a vent on it if it can't carry steam...

marcusjh

I got my terminology mixed up again - saying Main & vents... apologies (I edited )

Fred

That third pipe has to be a branch off of one of those other two mains. it may only have one or two radiator run-outs off of it. If it's a branch,It carries steam. The two mains that come directly off of the boiler header can both use a Barnes and Jones Bigmouth. When you figure out where that third pipe comes from, depending on it's length, it may need a Bigmouth also or it might be good with a Barnes and Jones Vari-Vent.

marcusjh

- so this will solve the issue of the Hoffman vent in my daughters room? I'm trying to understand how... I know more venting means a shorter heat-up time (which I plan to do), but does it also mean better pressure?

I can try the mirror trick on the Hoffman and see if it spews steam without it's screw and cap when heated.

Fred

Main venting allows the air to move out of the mains quickly thereby allowing more time, during a heating cycle for steam to move out into the radiator run-outs and radiators. Radiator vents should only be tasked with venting air out of those run-outs and the radiator itself. Not the additional air in the mains.
As for pressure, lower pressure allows steam to move faster. Good main venting keeps system pressure lower during the venting process.
If the Hoffman were spewing steam, it would be obvious to you. You'd see a condensation cloud spewing out of the top of that vent.

marcusjh

Thanks Fred. And yup, in case anyone is wondering, the screw hole IS also blocked when the 1A shuts - I just confirmed it with a mirror.

marcusjh

Okay.... so, to catch up - I've replaced the mains with big mouths, but I'm still having the same problem. My daughter's room was freezing this morning - and has been cold the last few days.
When I emptied the vent just now, blue drops came out - I want to say they were Turquoise blue. I'm wondering if the plastic container inside the hoffman 1A cracked? Either that, or the boiler stuff I put in last month is getting into the pipes (I put in a container of surgemaster b/c the water was bouncing badly, and I can't skim when it's cold).

I just ordered a new vent (Ventrite this time), but I'm still wondering if the boiler is undersized.

?

Fred

Dumping chemicals into the boiler is not a substitute for a good skim. If you need a skim, skim it. The blue stuff could be either from the vent or some carryover in the condensate from the boiler. Is it the same color as the water in your boiler site glass? Is that radiator pitched properly? Water in the vent will prevent it from venting, hence the cold room. Shake the vent out, pitch the radiator and see if that helps.

acwagner

Is this the only radiator with a Hoffman 1A on it? Is the room not heating because the vent keeps getting waterlogged or because the steam isn't reaching the radiator before the thermostat is satisfied?

I found on my system that when the system pressure is low, these vents were prone to becoming waterlogged or blocked with debris. I believe @ChrisJ had the same experience. If the vent keeps getting clogged you might consider just getting a difference vent type for that radiator. I switched to Gortons and I had less issues.

marcusjh

I've read good and bad about chemicals. And I had been meaning to skim it at the end of October/early Nov., but I just couldn't make the time. Plus, I'm a little weary on removing that big plug because I'm not exactly sure what size it is. It has never (to my knowledge) been removed, and I was told that I may need an impact wrench in order to do that.... I will admit though, up until about a week ago, the radiator was heating up okay (since I put the surgemaster in), but now I'm wondering if that stuff has run its course.

Site glass is light green- I've been doing a run-off every weekend, and flushing out the bottom gunk until it runs clear (/greenish). There IS condensate in the glass after a heating cycle, which indicates either the glass is cracked, or there's junk in the water again (would there still be even after using surgemaster?)

I bought all new hoffmans for a bunch of the radiators a few years ago, but as I discovered, they just aren't made like they used to be, so I'm going to be replacing some of the more sensitive radiators with ventrites. Do Gortons have larger vent holes? As soon as I remove the hoffman on her radiator, it begins to heat up within a minute - even if the vent is clear (if i can blow through it without any issues). I'm now wondering whether a second vent on her radiator would help do the trick (I have the "Lost Art" book, so I've been reading up).

marcusjh

Also - I've cleaned her vent with hot vinegar, and the top of it is off completely.

Fred

Condensate on the top half of the sight glass is typically a good indication that the boiler needs to skimmed. If that radiator worked up till a week ago, adding an additional vent isn't necessary, especially if the rad gets heat when you have the vent off. Either the vent is had, it is stuck closed or it is water logged. Is the radiator pitched slightly towards the supply pipe? If the plug on the boiler has never been removed, there is a good possibility that the boiler has never been skimmed. Skimming may resolve the problem. When oils lay on the surface of the boiler water, it makes it difficult for steam bubbles to break through. If you produce less steam or wet steam, it will affect distribution, in strange ways. I don't know where you might have read good things about chemical additives but most experienced PROs will advise against it, except maybe where you need to adjust PH or other water quality issue. As a cleaner, in a steam boiler, chemicals can cause more issues than they fix.

marcusjh

I don't know where I read 'good things' either - it was probably somewhere on here - but in any case, yes, the radiator is pitched toward the feed pipe. I won't know much more until I get a new vent on it, and I won't be able to skim until at least after the kids go back to school. but I'm not sure I want to mess with removing that plug until spring either.

marcusjh

Swapped out a vent from another room - seems to be working normally. I still have to keep the top off of it in order for the radiator come up with everything else. I'll try to skim at some point when the weather gets a little warmer. The ventrites came, and are way easier to use than the Hoffman 1A's - they just aren't made like they used to be. Thanks all -- Happy NewYear

marcusjh

Update:

Big mouthes are installed - Ventrites installed - but everything still takes about 45 minutes to an hour or more to heat up. I'm guessing the reduction from larger piping, to smaller piping, as well as that three-pipe set-up has a lot to do with it. AND, I'm not sure why it's piped this way. After it hits the vents, the steam has to travel down about 5 feet, go across that short horizontal pipe, into the third, and heat the upstairs...

ethicalpaul

Can you break down that “everything takes 45 minutes” into chunks?

How long from fire to when you can feel steam at the header? Then how long before steam gets to your main vent? Then how long till the fastest radiator gets hot? Then how long for your slowest radiator gets hot?

And is that from dead cold, or from a normal call for heat after a recent burn? Are you using a setback?

Do you still have a radiator that doesn’t get hot as fast as you’d like?

I’m bothered by this quote of yours: “but does it also mean better pressure?”

What is “better pressure” to you? Because to me the best pressure is like 0 to 1 psi at each radiator, closer to 0. The steam should give up its heat to the radiator and just be replaced fast enough to keep heat at the radiator. “Building up good pressure” is a contradiction to me.

Pressure just makes your pressuretrol shut off your burner and cycle. Required by 95% of our oversized boilers, but not the ideal!

Also please don’t hang a bucket off your sight glass valves 😅

marcusjh

Hi Paul-

Going backwards:

The pail is to catch drips from the sight glass bottom plug. It doesn't drip as much as it used to, but also, the run-off valve used to drip quite a bit (-although, I believe the city has since injected more sodium into the water, so nothing drips as much as they used to).

I've since purchased Dan's Lost Art book, so I'm educated about pressure. When the heat reaches temp on the thermostat, the pressure isn't more than 2 ounces (via 3psi wiki gauge).

Anyway- from a Warm start (maintaining heat on cold days) - takes about 5-8 min for the steam to hit the header, 12 min to get to the main vents, seems like 20min to closest radiator, 28 min to furthest radiator, 35-40 min before things are comfortable. In the morning when the heat kicks on (automatic from 63 to 64), it can take about an hour.

Not sure if the vents are closed too much, or whether the piping is to blame.

If you look back at the photos I posted - the pic (with the baskets hanging) show the old vents - those have been replaced with Big Mouths. The center pipe, goes down to a short horizontal pipe that everything is connected to before coming back up (third pipe, carrying steam) to the upstairs. Is that a normal way to pipe a steam system? I'm wondering if when they added onto the house in the early 70's, the heating guys decided to cheat and use the returns as carry-overs to the upstairs pipe....? Also, the pipe size gets reduced - so maybe that's an issue as well.

Seems like everything gets heated up around the same time, but from what I've been reading, 40 minutes is way too long.

Thanks-

Marcus

ethicalpaul

I haven’t seen enough systems to know if yours is messed up with that center pipe but I think your times aren’t too bad.

I bet your close radiators see steam before 28 minutes, but that’s mostly a hunch. They start heating the room well before they get full of steam and their vents close

I think your 63 degree setback is too much but if you insist on it, just have your program wake time be earlier

marcusjh

The closest radiator probably is heating up faster than that -but I have the vent set way back to 1. We normally keep the heat at 64 during the day, so we can't go much further back than 63 - unless there are thermostats that you can program like: 64.2, or 64.5, etc.

ethicalpaul

Ahh I understand. Well all I can say to that is that if my heat was set to 64, I'd never be comfortable due to being yelled at!