My Story - Saving another steam system

mikeg2015

After lurking on here for a while and picking up tons of great info, I thought I'd share my experiences.

We bought a 1907 brick, 2 story home in Iowa. It had the original 1 pipe steam system. Originally coal, oil burner conversion probably added in the mid 40's when I think they stopped having live-in servants to shovel coal (found a oil nozzle laying around), then later I'd suspect a gas conversion, and now has a 35 year old "modern" HB Smith G300 boiler... that of course isn't piped correctly per the manual.

I calculate 717 EDR. Boiler is 375k in, 300k out on ~100' of 3" header, with a single steam outlet. It's about one size too big, but did have ZERO pipe insulation in the basement and has a 42' clay tile lined chimney sized for coal, so INSANE draft!!!

What i did:

1) Added vaprostat on operating (24VAC) controls, pressuretrol left on 120VAC for high limit
2) new intermittent ignitor, flame sensor/pilot assembly, pressure adjusted down to 3.5" (was at 5"! and roaring)
3) replaced all air vents with a mix of Gortons, varivents and 1 TRV for a small toilet room.
4) leveled a 8 section wall radiator that had dropped 3" on the non supply end....probably 30+ years ago...took 30' to fix with a garage floor jack and a 2x4...sigh! Also lifted up a couple radiators that were spitting even with new vents.
5) Cut out a rusted in Hoffman 75 and added a Gorton #2 & 2 #1's but still need more venting to balance it. MAy clean up the Hoffman and add a varivent too. It had a mix of Hoffman #40, #2 vacuum vents, and 70A airport and adjustable. Pressure ran around 1psi I think.
6) LWCO was sticking on and off, replaced with a electronic M&D LWCO, put autofill back in service (it was unwired.. since 2003... with a sticky note to fill manually...sigh) So it had no working LWCO or autofill.
7) flushed and flushed and still flushing boiler and tried to skim it a little too out a 3/4" (no skim port)
8) Replace boiler drain, pressure gauge, added low range 32oz" gauge.
9) Installed upstairs and downstairs heat pumps for central air and supplemental heat for mild weather.
10) added home built custom boiler control panel and wired with relays to both upstairs and downstairs heat pumps as auxillary heat with OAT balance points.
11) Insulated the main header, and some to run outs (some were already insulated).
12) Add fresh air vent to boiler room to prevent negative pressure (have borderline radon levels (runs between 3-5 in the basement, long term average 3.9, but 1st floor is <1)
13) added powered flue damper, chimney cap and a manual flue damper to modulate draft. Chimney is 10" square and 40'+ tall. Based on charts, it's good for up to I think 500k BTU for natural gas atmospheric.
14) Added CO detector near boiler room. Need to get one with an relay output and/or add a draft switch to be safe. Open draft boxes/hoods scare me a little. But with a chimney cap, are least critters can no longer build nests in the summer.

System never builds more than about 1.5-2oz until it's heated all the radiators, which takes around 30 minutes from a cold start, 20 from a warm start. Hasn't been cold enough to hit the 5oz cut-out I have it set at. There's no equalizer, but with the low pressure and header is 36" above water line, so steam seems fairly dry. most noise is from an very long run out, to the 3rd radiator on the loop that probably needs more insulation or radiators that need more pitch. Other than expansion noises, it's pretty much silent.

So just a little more work to wrap it up, but it's a sweet system. Hopefully the boiler lasts another 8-10 years. When I replace it, should be able to drop is to around 250k BTU using just a 15% pickup factor. Still need to add some reflective insulation behind a could radiators on outside wall, seal some more air leaks, install some storm window panels that were left off, but the heavy lifting is done.

Just another success story. I could have easily installed a furnace downstairs and heat strips for the unico and abandoned it. But the heating is so nice and warm. hot radiators at 65F ambient feels the same as forced air at 68F.

Feel free to shoot any questions. I'll add some photos later.

Danny Scully

I read nothing, I want photos

mikeg2015

mikeg2015

Wish they hadn't painted them poo brown. Ugh. There's 5 more painted that way in the kitchen, master bed, 2nd bed and laundry room/servants room/4th bedroom (not sure what it's original function was) The tall one pictures is in the dining room and could use a good 2 tone paint job. Maybe black sections with gold or silver for the doors. The doors don't quite latch I'll have to glue on a shim some time. Paint is just mid grade latex paint, and seems to be doing quite well. I think it's limit is 200F, which in reality, the surface temp probably doesn't get much above 205 with the low pressure I run.

The wall radiator just has a wood block with 3 lag bolt to replace the bracket that came out of the wall. Based on EDR, it's the largest radiator in the house. I was shut off when we moved in, probably hammered a and spit a lot. Ideally, it still needs to go up another 1/2", but it's at least level now. The radiator sizing, honestly is spot on. I think they used a combination of window area, outside wall area for the calculations.

Upstairs doesn't overheat either. It's pretty even. 291 upstairs, 426 downstairs. There's a full open attic. All brick construction, no additions, full basement with 8' ceilings, 10' downstairs, 9' upstairs. 3800sqft finished. Design temp is about 5F in this area.

Danny Scully

The only problem that I can see are those radiators. They are extremely dangerous to your health...but I’d be glad to come to Iowa and take them out for you. That’s just how serious I am about your safety

mikeg2015

I have one laying in the back yard. So heavy I can barely even slide it around. Not sure what happened. I'm guessing it has a leak between sections. They replaced in with a "newer" tube type without any Victorian styling and painted is a dark metallic bronze.

I didn't mention that I have a few valve stems that leak, but not much once warm or at the 1-2oz the system runs at. One I might fix today if I get a chance, since it's mild weather and I'm running on the heat pumps anyway. COP is probably around 4.5 right now at 50F. So figure about 153,000BTU/$1 of energy assuming $0.10/kw-hr. Boiler is around $0.9/100k BTU input for natural gas (haven't checked prices recently. But factoring maybe 5% losses to the basement and 80% burner efficiency, I'd say around 84,000BTU/$1. So heat pump is almost 1/2 the operating cost. As temps drop to 25F, COP falls to maybe 2.5 and I'm now break even at 85k/$1...but my rates effectively drop due to volume and winter pricing, so I'm still ahead a little.

I'll probably set the balance point downstairs at 20F and upstairs at 25F and call it good.

Will be interesting to see where my heating costs are. I think previous owners say around $600 in the 2 coldest months. I bet I'm a lot lower than that. The draft damper might save me $40-50/mo alone for all 5 months the boiler is warm. It's insane how much heat was going out the chimney. Now it at least in the basement and even better, the chimney stays warm longer and some of that heat radiates indoors. We have cupboards attached to it and it's warm inside.

mikeg2015

Note on that control panel. Green light is 120VAC line power. Yellow is the LWCO, red is the High pressure limit.

The thermostat is just a back-up but has remote sensors that average, it was my primary control, but not the upstairs and downstairs Lennox S30's cycle the boiler as Aux heat using isolation relays. Both have outdoor sensors. I might need to add a anti-short cycle timer for the boiler.

I'm adding a simple hour meter to the main gas valve so I can clock useage. Although, the only other gas appliance is a gas grill and stove, water heater is currently electric.

Waterbury Steam

Where in Iowa are you located? I’m located in Des Moines...there’s lots of steam houses in my neighborhood.

mikeg2015

I'm down in Keokuk. One of the old "mid-sized" mansions on the river. Originally had gas lighting and electric lighting. Still has most of the original knob and tube, in very good condition, fuse panel upstairs. Some lights are dual fixtures. Even found a little cast iron wrench hanging in the attic that your use to reach up and close the valves on the gas lights to turn them off.

Most people here take the steam systems out of service. Last house we owned 3 years ago, 2 blocks away had a 2 pipe system from 1925 with massive radiators with original metal covers. It was 3200 sqft but must of originally had around 800+ EDR. Had those valves on the inlets so you could balance them. By the time we got it, 1/3 of the radiators were removed. In it's place were gas furnaces 2x the size needed and ductwork 1/3 too small. I installed a really awesome Carrier Infinity dual fuel system with heat pumps and modulating furnace.

Lot of steam in Iowa.

mikeg2015

I'm still having trouble getting the main vented fast enough. I opened a 1/2" valve wide open and I still have some of the early runouts getting steam. There's just too much pressure drop to get to the end of the main. Master bedroom has a long run out and it's near the end of header. I might go a little unconventional and drill and tap a 1/4" NTP tap in the T fitting at 45 degrees, then use Varivent wide open on top of a 6" pipe nipple. I think I also need one more Gorton #2 as well at the main vent common header.

I wonder wit ha header this long, if originally designed for gas boilers, you'd have the header going 2 directions, then pitch it back to a center mid point, the return that to the boiler. So still a dry return.

EBEBRATT-Ed

Seems like it runs pretty good for a steam boiler that is piped like a hot water boiler

Fred

Don't mess with the pitch of the piping yet. Part of your problem (maybe all of your problem) is the near boiler piping. You really don't have a Header. Your riser, out of the boiler is tied right into your steam main. That main should then come off off the horizontal header. That will allow water droplets to fall out of the steam before it heads down the main(s) From what I can see, you have one large main that appears to loop around the basement with radiator run-outs off of it. It then becomes a dry return, after the last radiator run-out and drops down into the boiler.You also don't have an equalizer, which should run down from the end of the header, into where your return pipe is currently connected to the boiler. That equalizer will allow water from the header to drop back into the boiler and it will also equalize the pressure in the boiler with that in the header and equalizer to keep the boiler pressure from pushing water out of the boiler and into the return pipe.
Once the equalizer is installed, then your return pipe is tied into the equalizer, using a Tee, below the normal boiler water level.
I don't know where your vents are now but they should be somewhere, in the main, after the very last radiator run-out or on the dry return before it drops down into the wet return (currently into the boiler). All of those things should be corrected. Of course, if you if more venting is needed, it can be added but it all should be after the last radiator run-out. Measure the length and the diameter of the main(s) and then add enough venting to accommodate air removal. The best venting for the money (both venting capacity and quality) is the Barnes and Jones Big Mouth.

mikeg2015

Big Mouth is unfortunately showing out of stock. Main is 3", about 90-100', but I'll measure. I think if I max out my 3/4: tapping I'll be good. But I'd need I think another #2 Gorton or the Big Mouth if I can get one. Adding a vent further up is just something I thought I'd try. can always just plug it. Might be handy to have a pigtail and pressure gauge there for reference anyway. Then I can see the pressure drop in the pipe and the balancing challenges will become more apparent.

Adding a equalizer won't be cheap, will be a little removing pipes that have been in place for 35 years, maybe 105. Probably $200 in material I'd guess. I have a master plumber in town that could probably do ti for me, he's not a boiler guy, but a good pipe fitter.

Will it really make much difference? I'm not seeing more than a 1/2" drop in water level once it start steaming as I'm only reaching 1oz of pressure. I keep the water level a little below "normal" for a little bigger steam chest, but still well above minimum

Here' the thing, if I never build any pressure, so water line doesn't really change. I have zero hammering. First 2 radiators chirp a little due to some surging due to lack of equalize in the header there is a little bit of surging, but still only 3/4" of movement in the glass gauge.

Is there consensus to modify header to add an equalizer pipe on a 35 year old boiler? Just getting 2nd opinion. The "A" measurement is about 30" to the first elbow and 8" above that to the header, and there's a jog in the header that I assume is added for expansion and to create the pitch in the pipe

No water hammer at all, anywhere.

Jamie Hall

My opinion? And it's just that? I'd hold on the equalizer until you have to replace the whole thing when and if you need a new boiler. If it ain't broke...

However, I'd make very sure that my low water cutoff really worked -- and being a belt and suspenders kind of chap, I might add another one, somewhat lower, which was manual reset -- jut in case something gets crossways...

mikeg2015

I was planning on possibly rebuilding the original float type LWCO and putting it back in service. Maybe just on the 24vac controls side. But need to open it up first. Float was stick when I replaced it.

My thought was hold on equalizer for now until I replace boiler in 6-10.

BobC

You'll never know till you install an equalizer so it depends on how you feel about the whole thing giving your dealing with pipes that have been in pllce for 35 to 100 years.

The Big Mouth is showing in stock on Amazon right now so I'd up the main venting and see how that goes - a bigmouth equals 2ea Gorton #2's.

You also might want to think about using PMJ's method of shorter more frequent firings to see how that works out.

Bob

EBEBRATT-Ed

I agree with @Jamie Hall fix the venting and other minor issues and leave the boiler alone if your not having problems.

Putting in an equalizer makes no sense as it would all have to be changed if you install a new boiler. If the system is quiet and the water line stable your good to go.

This is another case where "non textbook" piping is working ok. We see that occassionally

I wouldn't disrupt a 35 year old boiler you may cause other problems

mikeg2015

BobC said:

You'll never know till you install an equalizer so it depends on how you feel about the whole thing giving your dealing with pipes that have been in pllce for 35 to 100 years.

The Big Mouth is showing in stock on Amazon right now so I'd up the main venting and see how that goes - a bigmouth equals 2ea Gorton #2's.

You also might want to think about using PMJ's method of shorter more frequent firings to see how that works out.

Bob

That's funny, it just came back up on Amazon. Done! I already have a home for it on the main vent "riser". I'll just use a varivent there for now temporarily. I also bought a 15" (8oz) gauge, as the 16oz gauge I have still barely registers any pressure.

I'm having an occasional flame sensor drop does that count as intermittent firing? Brand new flame sensor, not height adjustable and messed with the pilot flame height, but still does it. Was worse until my HVAC contractor checked the manifold pressure and it was 5"! not 3.5". Wow it was a lot quieter after that. Only drops out once the boiler is up to full temp. Then only once every 1-2 minutes.

You mean install a cycle timer with like a 10' off 1' on. I actually have an extra timer that I think can do that laying around. Might stop the flame drop out issue as the boiler might stay just under full temp except during very long runs. So basically you downfire the boiler using very, very low frequency pulse width modulation.

I forgot to mention that the manual says for a 6 section G300, you are supposed to have a second connection on the header. What's funny is the installed underlined and circles several things in pencil and made a few notes, but regardless, decided all that extra near boiler piping wasn't necessary.

mikeg2015

Update:

Did some measuring. About 95' of 3" header. That puts it around 5 cubic feet of air. But I'm only seeing 1oz of pressure at the boiler, probably a little less at the main vents after friction loss. I have currently 3.1 CFM of venting capacity at 1oz. With the Jones Big Mouth replacing a Varivent, it will be around 5.3 CFM. For experimentation, I drilled and tapped two 1/4" holes. One on the header about 1/2 way around the basement, the second on a 1-1/2" elbow on a very long run-out to the master bedroom. The run out is probably about 15' horizontal and 13' vertical. I'll put a Varivent on that one, and maybe a Varivent on the other.

I timed it:
1) 5:00 - start making steam from a fully cold start it took about 5' to reach boiling (500lbs of iron and about 16 gallons of water take time to heat up).
2) 14:00 - steam produced to reach the main vents on a cold header.
3) 30:00 - About 30-50% heated on the radiators, master bedroom was stubbornly at 25%.
4) 45:00 - At about 75%-100% on all the radiators... except just 50% on the master bedroom. It was only 50F outside and the downstairs was had heated up from 69F to 75F, so I gave up. Pressure still never rose over 1oz.

Vents on the first two downstairs radiators whistle and chirp just a little. All others are silent.

CKNJ

My first house, a 1923 center hall colonial was very similar. It was a single pipe with a 3" main that ran continuous around the perimeter of the basement (90' long) with a downward pitch away from the boiler to the return. When I was re-insulating the pipes, I found a "T" fitting at almost exactly the 45' mark. I concluded it had to be for a midway vent for the system as there was no reason to put a T at that point (and there was a reducer bushing on it). Vent must have failed at some point and they just plugged it. Putting a midway vent in that system was a game changer.

mikeg2015

Interesting. The plugs look original to me, no reducers. But maybe they were removed early one, or just never used. But the locations are very good spots for mid vents. But also locations where i might have expected a run out to be for a radiator on the upstairs landing, maybe the upstairs foyer for the other.

I might switch things around and enlarge the one mid vent I have. Still not venting main fast enough, but also could be venting radiators too fast.

After adding the Big Mouth, I now run at 0.5-0.8oz until the header fills, then it hovers right at 1oz.

First 2 radiators still whistle/hiss a little, last 3 radiators heat up a little slow. Everything else is pretty good. Getting closer.

SeymourCates

Your attempts at reducing the time for steam to reach the main vents will result in no improvement. The time of 15:00 to go 90' is nearly 3X what should be the performance on a cold start. The issue has nothing to do with venting and everything to do with wet steam. It is taking forever to move 90' when, in theory, it can move at 20'/second if condensation doesn't hold it back. Even if we assume that the main requires 20K to fully heat it to 212F, this occurs in 4 minutes so we expect steam to reach the main vents in less than five minutes on a cold start and about 2.5 minutes on a hot start. The near boiler piping with no effective header and no equalizer is killing the efficiency of that system and it can't be magically corrected with the largest vent in the world.

mikeg2015

Keep in mind, the first 7 minutes was heating the water. it was about 8' to heat the pipe and vent.

I calculate around 42,000k BTU to heat the 3" cast iron header and fittings, around 800lbs by 130F. Which interestingly enough, would be right at 7 minutes. SO if it vents at 8-1/2, that puts me right at 1.5 minutes with a "hot start", which is roughly where I calculated I should be.

However, the venting noise on my first 2 radiators does support I'm still a little wet. May just bite the bullet and re pipe it next spring. It overall does work well and my vents have maximized the 3/4" tapping regardless.

I'll do a little more re-balancing then give up for the season. the house has so much thermal mass that ultimately, that precise balance is not a big deal. I need to spend more time and resources on some new storm windows, door seals and sealing a few other air leaks. My humidifier is woefully inadequate with this high of ACR.

PMJ

SeymourCates said:

Your attempts at reducing the time for steam to reach the main vents will result in no improvement. The time of 15:00 to go 90' is nearly 3X what should be the performance on a cold start.

Perhaps you might define what you say is a cold start. Cold start to me is the entire system boiler and all is at room temperature. Starting from there your 5 minutes to steam at 90' is pretty optimistic in any system.

SeymourCates

The specific heat of iron is .11 BTU/lb/°F. You require 88 BTU/°F. for the 800 lb. steam main. That's 11,440 BTU for the 130°F climb.

The time of 5:00 is measured after steam reaches the header. The time to heat the boiler to 212°F is excluded. The variable of the boiler itself must be excluded as all of them are quite different depending on their age and construction.

This time should easily be achieved with a boiler of that size if the steam is dry and the vents are sufficient.

PMJ

SeymourCates said:

The specific heat of iron is .11 BTU/lb/°F. You require 88 BTU/°F. for the 800 lb. steam main. That's 11,440 BTU for the 130°F climb.

The time of 5:00 is measured after steam reaches the header. The time to heat the boiler to 212°F is excluded. The variable of the boiler itself must be excluded as all of them are quite different depending on their age and construction.

This time should easily be achieved with a boiler of that size if the steam is dry and the vents are sufficient.

I see. Then I read the OP to say that from your start point he was at 9 min to steam at the mains not 15.

Anyway, you will grant me that the time from steam at the header to the main vents from a true dead cold start(everything at room temp) is much longer than after a restart as a properly insulated main stays considerably above room temp for quite a while.

For the above reason all these times are quite relative.

SeymourCates

Agreed. 9 minutes is still excessive for such a large boiler.

Of course. Your approach to running the boiler several times per hour minimizes the time to a significant degree. A well insulated (1") iron pipe will fall to approx. 150F in 30 minutes. The energy required to raise it to 212F is a fraction of the cold start requirement. Those with uninsulated mains pay dearly each time the boiler fires.

mikeg2015

Very true. Wasn't trying to debate, just clarifying.

I'm in the process of downsizing a few radiator vents to make it a little happier. The Hoffman 1A make the lease noise with slightly wet steam. I might also get out my floor jack and add some height to those 2 radiators on one end. They are pitches almost flat right now....which was probably OK for nice slow even coal heating 110 years ago with a powered damper for the thermostat, then probably a modulating damper based on pressure. The thermostat wire I replaced looked original, same type and condition as the door bell ringer circuits.

PMJ

SeymourCates said:

Agreed. 9 minutes is still excessive for such a large boiler.

Of course. Your approach to running the boiler several times per hour minimizes the time to a significant degree. A well insulated (1") iron pipe will fall to approx. 150F in 30 minutes. The energy required to raise it to 212F is a fraction of the cold start requirement. Those with uninsulated mains pay dearly each time the boiler fires.

Right. Further the vaccum keeps boiler making steam and steam flowing to the rads keeps mains hot rather than room air cooling rads and mains down between burns. When you stop to think that it is most of the hours each day this difference is at work you begin to appreciate how big a deal it is.

mikeg2015

Things are pretty well balanced right now, but I'm not venting based on radiator size, mainly on location, but it's balanced pretty well overall. It took over 1 hour from a cold start, but I finally heated all the radiators, and pressure started building. I shut it down at around 8oz, if took maybe 20 seconds to fall to 1oz, and restarted, ran for maybe 2 minutes and repeated. Still have noisy vents above 3oz. I think it's mostly dirty water causing it. The longer the system runs, the dirtier the water gets. I think the system will take a few weeks to get cleaned.

MilanD

Sounds like your wet returns can use flushing out. That's where all that dirt is coming from.

mikeg2015

MilanD said:

Sounds like your wet returns can use flushing out. That's where all that dirt is coming from.

So what's the best strategy to clean them? Just keep draining a little off the boiler drain and LWCO blow down? Most of the solids seem to settle out. I think I have to just keep draining a little off every few days.

I think not having that 2nd connection of the boiler is hurting me the most. Just too much velocity right off the boiler.

mikeg2015

Quick Update:

Drilled and tapped a 3rd vent on the main. 1/8" and used a Varivent on it. This one about 1/3 of the way down the main. The 2nd is about 2/3rds, and the 3rd added tap is a varivent on the long runout to the master bedroom near the end of hte header. I think it's the longest run out of any. It had a varivent on that radiator.

I then started downsizing some vents.

HUGE improvement in balance. HUGE! (to quote our articulate commander in chief). Just a few more swaps and I think I'll have every radiator heating at nearly the same rate. Just a little noise from 1 radiator. None from the others. Partly that because the vent is near the top of that radiator because the lower tap location is right by a vertical riser to a upstairs radiator. Might be able to tap it and add a short pipe nipple. Not ideal, but think it would work better than how it is now.

Going to try skimming all day tomorrow since it's warm outside. No skim port and so I'll have to make do with the 3/4" valve on the upper sight glass level.

I think slowing the radiators a little more should get me there. Will cause more steam to stay in the main until it's fully vented.

MilanD

Sorry, I'm just now seeing your question. With your return being mostly dry, your plan to flush the boiler a bit at a time is probably good enough. If you have a way to access the boiler to be able to wand-clean it, that would be also great. From looking at your pics it looks like you do not have access to the boiler for wanding. At some point in time, you could repipe the return and replace the ell that's there now with a tee, one run coming straight out to give you access for wanding.

gerry gill

i love the dining room radiator!!!!!!!!!!!!

SteamCoffee

That DR rad is amazing, the walls hung units are nice too. Any indentifying markings on them? The detail is quite unique...thanks...

mikeg2015

SteamCoffee said:

That DR rad is amazing, the walls hung units are nice too. Any indentifying markings on them? The detail is quite unique...thanks...

Most are marked American Radiator Co. I have 2 different models series I think. Some a taller 3 column. Others are short, but long 5 column under windows. One is very long 25 section unit, I think 96 EDR in the family room. Must be at least 600lbs. But I was able to lever it up with a pipe wrench to put some pennies under the feet. The dining room unit i guessed at 84EDR... because of the warming box. 3rd largest is that wall radiator at 56 EDR. Lots of windows and doors in that area.

Oddly that huge radiator hasn't really needed more venting since it's a shorter runout overall and located just before a 90 degree turn after the longest straight section on the header. '

I think for balancing, you have to remember that the steam may be moving at over 2000fpm, so every turn, fitting, etc will create back pressure. The dead men knew this and they followed guidelines on distance to elbows, and were very, very deliberate about runout spacing and location.

... if only the same attention to detail was made with HVAC systems, I think you'd find that forced was less drafty, silent and more comfortable. But it's rarely done well.

mikeg2015

NOTE on heat pump integration:

I was able to use one relay to allow heat strips to come on during defrost, but disable them normally, and trigger a relay for the boiler. I also added a toggle switch to enable the strips manually if needed. Fan speed runs are a elevated "Emergency Heat" speed. I set that as low as possible. Not a bad thing as it helps even out room temperatures anyway.

An adjustable delay on break timer is preventing boiler short cycling after a call for heat or if the vaporstat reaches high limit.

All this could have been done with that little PLC, but this works fine for now.

gfrbrookline

Had a similar problem with my system, 2 50' mains, uneven heating, some very slow radiators and some short cycling on pressure. After having my local contractor tell me to turn the pressure up I decided it was time to tap into the forum's resources and get someone who knows what they are doing. Ryan aka NewEnglandSteamworks came out looked at the system for all of 30 seconds and started adding vents to the mains. I now have 3 Big Mouths + 1 Gorton #1 on the slow main and 1 Big Mouth, 2 Gorton #2's and 1 #1 on the slow main, he used vents I already had. My system is now balanced and the run time of the boiler went from 30 minutes with 2-4 short cycles on pressure to 12 minutes max on tstat, no short cycling. It is also almost completely silent. The only sound I hear is the clicking of the ventrites closing, no more hissing or banging.

It's all about getting someone who knows what they are doing and venting the mains. My Vaporstat is set at 16oz cut out 2oz cut in and the gauge doesn't go above 8oz.

mikeg2015

Cool! I'm unfortunately pretty far from any pro steam resources. Mine never sees 3oz until radiators are completely heated.

I'm hesitant to add another large tapping.

But I think I need to vent radiators even slower. Most are #5, #6 but last 2 are C & D. Got it pretty close.

I think I'll wait 5-7 years for boiler replacement to go any further.
1 size smller boiler and equalizer, dryer steam and it's will be perfect. Nearly silent now anyway. Just the very faint rush of gas and steam resonating through the pipes.

gfrbrookline

All of my main vents are on antlers off of a 3/4 fitting, worked wonders.
I would suggest either ventrite #1 or Hoffman 1A vents for the rads. They can easily be adjusted so you can fine tune all of the rads. I tried the Gorton and Mom but wasn't thrilled.