Main vent replacement- add others somewhere?

jch1

Happy New Years to everybody. I have a couple of quick questions. The guys who installed my new boiler did not replace the main vent. I highly doubt that it is functional, as I have been listening to all of my radiator vents (which I just replaced with Hoffmans and varivalves) whistle or force air out now for a solid 20 minutes since I turned the system back on. I have a one pipe steam system with a single main that exits the boiler and ultimately goes up to another floor.

A quick aside- I counted twelve pipes which extend vertically from the main pipe, but I only have nine radiators in the house, so at some point some of the connections must have been closed off.

The dry return has a vent that's on a six inch vertical pipe. I was told by a separate contractor that I would need a Hoffman 4A. Another contractor recommended a Hoffman 75. Upon researching I figured I would just go with a Gorton 2 to be safe and being mindful of the fact that this is the only vent I have. Also, I'm seeing identical prices for the Hoffman 75 and Gorton 2. Would this be wise? Alternatively, I was thinking of 1) making a branch off of that vertical pipe and putting two Gorton #2s on there, or having someone cut the main pipe at some location so I could put a vent in. That seems like the most costly job.

Attached are a couple of pictures for clarification.

Thanks

J

Steamhead

How long is the steam main, and what pipe size?

jch1

So I did some more investigating. The pipe in the 4th picture appears to just be dropping down into another room in the basement, so it looks like it is just one large loop.

The loop appears to be 76 feet long, and the outer diameter varies from 3" at the header to the pipe that leads to the other room, then drops down to 2.5" OD when returning from the finished portion of the basement. I have additional pictures if that would help.

jch1

Because I only have one main, it looks like I should be okay with just replacing the current vent with a new vent or two. I wonder if I could get away with one Gorton 2?

jch1

I understand. Are you suggesting that I just put three on a tree to replace the one existing main vent or somehow installing them at different locations?

jch1

So I'm clear, there will be a substantial difference between two G2s and three? My concern is that the additional cost will not result in a reasonable benefit to the system.

BobC

Try measuring the time it takes steam to get from the header to the end of the main with what you have now. Then measure how long t takes with one and then two Gorton #2 vents. The third will not be as effective as the tst or second but if you do the math you will find at what point adding venting does not make sense.

BTW my 2" steam main is about 12 ft long (about 0.26 cf) and I have 2ea Gorton # 1 vents (about 0.66 cfm), I started with 1 Ventrite 35 (0.11cfm). Figure out the volume of air in your mains and do the math. You can buy the vents or you can pay the gas company, it's your choice.

Bob

nicholas bonham-carter

Don't forget in your calculations to add in the volume of air in the steam chest of the boiler.
You can never have too much venting.--NBC

jch1

Thanks for the advice guys. I guess 3 is the way to go. Just gets pretty expensive.

jch1

Haha yeah. I will say that I enjoy learning about all this because, unlike many of my other hobbies, this one has the potential to actually have a positive effect on daily comfort and enjoyment of my house.

I have two other questions (for now). First, I was going to insulate at least a portion of the main. HD is showing my size as being $10 per 3 ft of fiberglass insulation. Is this about what I should expect to pay? According to threads a few years back, it was in the 5-6 dollar range.

Second, I mentioned this briefly before, but my Peerless 64 has a CycleGard LWCO which shuts off periodically to perform the stupid system check. I don't have the "Smart Cycle" wired using that extra "burner" terminal, and would like to do so. Could somebody explain where I need to couple this wire to on the burner controller side? The instructions are terrible, and the guys who installed the boiler said "oh, you don't need that, and it isn't even available for your LWCO (despite there clearly being a terminal for the wire). If it's not as easy as it seems (i.e., simply tapping a wire in somewhere...), I guess I may just look into a new LWCO such as the SafGard, which is the same one but simply lacks the intermittent level test. Any help there? I know several experts have experience with these LWCOs, so perhaps I should just reach out directly to them.

jch1

BobC said:

Try measuring the time it takes steam to get from the header to the end of the main with what you have now. Then measure how long t takes with one and then two Gorton #2 vents. The third will not be as effective as the tst or second but if you do the math you will find at what point adding venting does not make sense.

BTW my 2" steam main is about 12 ft long (about 0.26 cf) and I have 2ea Gorton # 1 vents (about 0.66 cfm), I started with 1 Ventrite 35 (0.11cfm). Figure out the volume of air in your mains and do the math. You can buy the vents or you can pay the gas company, it's your choice.

Bob

I don't think I can do this because the vent doesn't appear to be operational, unless you're suggesting just removing it? Speaking of which, any advice on how to safely remove the vent and nipple? its on an 8" nipple, so I am planning on reducing that to a 6" to allow for additional clearance of the Gorton 2s.

vaporvac

I can only help with your first question as I've been calling around and checking online for pricing myself. That price is high. I found the best deal at a local place specializing in insulation. It was the same as the cheapest online place quoted here and no shipping. It was quite a bit less than HD and that was for 2" insulation on 2.5" piping. Hope that helps.

jch1

It does, thanks. I'll continue poking around.

jch1

That was one of the websites I came across. Good to see it's a reputable seller.

Fortunately, my CycleGard is wired for 120V, so maybe I'll come across a good sale. I would ask about warranty issues, but the contractors didn't even know that this unit had that feature, so I highly doubt they would realize anything was replaced if I do a good job.

vaporvac

http://expressinsulation.com/
This in another online place with cheaper prices that some here have ordered from in case you can't find what you need locally.

Captain Who

@jch1 - I have the 24V CycleGard wired for the SmartCycle. I highly advise doing this. If I recall correctly, I just had to run a wire from the CycleGard to the hot on the gas burner valve.

I'll dig up the instructions and review it.

Captain Who

Lots of people have less than optimal water chemistry (causes foaming) and near boiler piping due to incompetent installers (causes tilting of waterline). Until everything is set up to be right, which can be prohibitively expensive for some folks in the near term it is a nice feature to have the extra protection. For example (especially with inadequately sized near boiler piping and main venting), the waterline can tilt greatly while steaming giving a falsely high waterline at the probe and sight glass.

My instructions are annoying (24V CG400 CycleGard) in the respect that they say: "This feature enables a full burner run cycle (10 or 20 minutes, depending on model) prior to the first Intermittent Level Test." I mean which is it???

Unfortunately in my model they had the circuitry built to be 10m and I'd really like to try to mod it to be at 20m or even 15m like you said. That way it wouldn't be doing this under steady state conditions during the day, but it would still do one or two shut downs during recovery from a heavy setback. It's only a 90 sec shutdown and that I can deal with as a minor inconvenience that may have some safety benefits.

Captain Who

I also have a practically new 120V CycleGard (original install not by me) which I replaced with the 24V one to solve some problems associated with my digital thermostat install some years ago. I'll be damned if I'm going to buy yet another one, at least right now. I really want to figure out how to modify this thing to adjust the timer setting after the burn starts.

BobC

i think they use digital circuitry in the timer area and the chips in mine did not look like industry numbers. let us know if you find a way to delay or defeat the timer function.

Bob

Captain Who

Maybe an additional circuit that would fool the CycleGard into thinking the Burner Valve was there but hasn't fired yet. Then there would be a user adjustable delay feature built in. For example, if you had the 10m SmartCycle enabled unit and you wanted a 20m delay, you could dial in an additional 10 m of delay to equal the 20m.

This would have the advantage of allowing people to keep their existing CycleGuards but they would also be able to adjust it from 0 offset to whatever they wish. Maybe you could effectively eliminate the Intermittent testing if you wished, to make it effectively a SafGuard.

Captain Who

PS: I suppose a 24V PWM circuit could do it.......Eliminate the Intermittent Testing feature that is. Would be pretty cheap to do really.

Captain Who

Scratch that.......this is already AC. This is a job for MarkS or archibald tuttle.

Captain Who

One more try.......a simple timer circuit, for example to eliminate my 10m delayed Intermittent Test I could use a 5m timer circuit that would apply 24VAC pulse (from the transformer) to the Burner terminal in the SmartCycle circuit every 5 m. So every 5 mins it would reinitialize the 10m timer to the SmartCycle. It would therefore never be allowed to get to 10m, so no Intermittent Testing.

jch1

Again, thank you all for the advice and suggestions. I think I may look into getting a SafGard. It seems like it would be as simple as removing the wires from the terminals on the CycleGard and just putting them on the same ones for the SafGard.

I guess I have another question. When the boiler is on, the water level in the sight glass drops down 3-4 inches. It's almost completely clear, with little gunk at the top. I'll definitely be skimming it in the near future, but could I have other issues with piping? I'm also hoping that some of it is due to my venting being inadequate (I have three Gorton 2s en route). I'm having trouble removing the existing vent and nipple, so I may need to get someone in here with heavier duty tools. I guess the question then is could the new venting and insulation help with the water level dropping?

Captain Who

I just checked the price on those SafGard's and they're up around $160......ouch.

Could you post a picture of the side of your boiler with the sight glass and CycleGard? I need to see the relationship of the near boiler piping and hartford loop to where the lwco is, etc.

My Peerless 63-04L does the opposite. The water in the sight glass rises by about 1", not right after the burner fires necessarily, but after there starts to develop some steam in the steamchest. I believe it is due to the waterline tilting because of inadequate vents and insufficient near boiler piping.

Captain Who

At what point in the firing cycle does this happen? Right at the beginning, before steam is generated, towards the end of a long burn? Need to give more details.

jch1

Right at the beginning. I'll record a video shortly

Captain Who

What is the height of the lowest part of the dry return above the NWL (normal water line)?

jch1

39 inches from the actual line provided on the sight glass. I'll have a vid uploaded shortly, but here are some pictures I just took. You'll see the sight glass is on the opposite side as the equalizer and the hartford loop. Also, the contractor came back to change the piping because I previously had a long nipple which was replaced and lowered.

Fred

That water drop in the sight glas is most likely the result of oils in the water. Skimming will likely resolve that. How old is the boiler? When was the last time it was skimmed? Has there been any pipe repairs since its last skim? Do you see any moisture (water droplets on the top portion of the sight glass? Any of these, coupled with the gunk you see on top of the water in the sight glass are pretty good indicators that it needs a good skim.

jch1

The boiler is two months old. They skimmed it once about two weeks after the install, and then about 2-3 weeks later, they replaced some of the piping such that we now have a short nipple.

jch1

This upload may take a while, but it seems like a drop of that amount is normal/expected?

jch1

Well then, I suppose this upload isn't necessary. I thought I remembered seeing people say it should really only be dropping an inch or so.

Anybody see any issues with the piping (save for the step over on the equalizer)?

Captain Who

@jch1 - It seems odd that you would get that much of a drop right at the beginning of the burn cycle. You say it is before steam generation as well? If that's so, it must be an extreme foaming issue, I'd say. Pretty hard to say what the actual water level is at that point in time with that much foaming going on.

So they lowered the Hartford Loop? What is the vertical height below the NWL to the top of the close nipple? Not so easy to measure with your piping arrangement. Best way is with a liquid level. If the true water line drops below that level during steam generation, it will prevent condensate from returning to the boiler and will cause a rapid drop of true water line as the burn progresses.

Captain Who

I don't like the "stepover" in the equalizer either. It would be better to put in a 45 after the reducer and another 45 to have a decent vertical drop above where the close nipple is.

Also, it seems like the header is awful small. I've heard people here say that the takeoff for the main should be 15" after the riser from the steamchest. With a header as short as yours that isn't possible. The idea is to make it more likely that only dry steam makes it up into the main.

Fred

Is there a significant amount of bounce in the sight glass water (more than 1/2 to 3/4")? If so, skim it again. My boiler is about 400 MBTU and the water only drops about 2 inches total but it is an older boiler with a much larger water capacity, probably around 25 gal. (to the middle of the sight glass. It is an older Burnham that is filled to 3/4 the way up the sight glass).
Can't see a good portion of your piping in that picture. You have only 1 Main? or does thaat one riser go up and tie 2 Mains together? If it ties two mains together, they each should have dropped down into the Header individually.
It Would have been nice if they had used both risers out of the boiler.

jch1

So I was wrong. It doesnt start moving for a few minutes, which I assume is the time it takes to turn the water to steam. Here's a video, and my apologies for the first few minutes. It begins moving at the 1:20 mark.

http://youtu.be/a7qFKKuXt6o

And no, they didn't lower the hartford loop. Before, the equalizer pipe just went down vertically and then extended horizontally to connect to the hartford loop and drain pipe, so it was a 10 inch nipple that was well below the required 2-4 inches below the water line. they repiped it (with the step in the equalizer) to 1) have a short nipple present and 2 raise the pipe so it was 2-4 inches below the water line.

jch1

Thanks again for the help, guys. Yes, I only have one main that loops around the entire basement. I may not have my terminology correct here, but it's a 3" header (the pipe that leaves the boiler?), and it extends 26" above the indicated water line on the boiler. The riser (the pipe that extends vertically to the main?) is another 16" tall.

Fred

It's not that bad but it does need another skim. I think I even saw a drop of condensate drop from the top into the sight glass water. A good slow skim should take care of that.

Captain Who

It didn't seem like it dropped that much to me, at least for the length of the video. You said 3 to 4"? Or did you mean 3/4"? On my boiler it is 6" from the NWL to the bottom of the sight glass. Anyway, it looks like mine used to look before I got all my return pipes pitched correctly and my radiators tilted properly and my water nice and clean. Mine was installed around 10 years ago and was NEVER skimmed, partially because the idiot installer blocked the skim port with a huge (no reducer) copper equalizer. I guess it has taken me this long without proper skimming to get everything clean. Now it looks plenty dirty in the sight glass but it is pretty much steady as a rock.......maybe 1/8" to 1/4" of surge tops. It does rise rapidly to a stable level about 1" as I said due to waterline tilting as soon as steaming occurs.

jch1

Oh yeah, it drops more at about the same rate. During a particularly long cycle for example, if the boiler runs for 30-40 minutes (with the LWCO turning on 2-3 times intermittently), I've checked the level to find that the water level is about an inch from the bottom of the sight glass, which is more in line with it being a 3-4" drop.

As far as skimming goes, all I need to do is open up that port and have the manual valve open such that water slowly trickles out? Do I need to bring the water heat up a bit before beginning? How do you know when you're done? When the water is clear?