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Like my beautiful, moody ex-girlfriend...SOS in Portland!!!

rgargoum
rgargoum Member Posts: 20
edited February 2020 in Strictly Steam
Wow!!

I purchased "The Lost Art" and read the relevant chapters last week. I have a single boiler with a manifold serving 4 one-pipe mains. The first-floor apartments have shorter dry returns and longer risers than the second-floor apartments.

I understand the system a little better, but I mostly now understand that this is truly is an art, an art which necessitates constant attention.

I am as willing as anyone to invest in a system to make it function better, but I'm afraid that I'll be investing in things that don't necessarily make my system function better, or make it function worse. So far I've invested in bigger main vents (4 big-mouth main vents, at the ends of my returns, and insulation for my some of my previously un-insulated mains).

I am delaying in doing a couple of things:
1. replacing all the vents on all the radiators in the house
2. insulating all my basement pipes

I think I truly need an expert and a whole-system evaluation.

Why am I delaying?

1. I have delayed insulating some of the downstairs piping. One reason is that I wondered if the people who installed my new boiler calculated the un-insulated pipe into the overall heating equation. I seem to have read some things to this effect on the wall and in "The lost art." If it was calculated into the heating load of the house for all the basement pipes to be un-insulated, wouldn't insulating the pipes set me up with an over-fired boiler and potentially a problem with short-cycling?
2. I was having a problem of the boiler spontaneously over filling throughout the winter, but the system was at least stable for 2-3 weeks (not sure why), so I didn't want to change anything.

UNTIL LAST NIGHT!!!

Again I came home to whistling vents on the radiators in my second-floor apartment, and went to the basement to find the water line way over the sight-glass, water spilled all over the basement floor, rusty discolorations at the lips of two of my big-mouths, and the crappy pressure gauge reading 5 lbs of pressure.

This time I emptied at least 15 gallons from the boiler, but the line is still way above the sight-glass and the pressure hasn't budged.

I am truly baffled as to where this water comes from, and therefore scared of draining any more off. My automatic electric feeder stays at the same number where it has been for weeks, 051. (What is this 051 gallons? liters? hundreds of gallons? I am only confused because if I removed 15 gallons from my system, where did it come from? why is this number the same?

I am so puzzled.

1. Where is this extra water coming from?
2. Why doesn't my electric feeder's number change?
3. Why does my pressuretrol allow the pressure to get up to 5 psi? (It's set to cut-in at 0.5 with a diff of 1)
4. What do I do next?
5. Why does this happen? Was it because I lowered my thermostat to 60 for half a day when I wanted to open the windows for a few minutes to air out the apartment? What's going on???

Baby, I want things to work, but you have to stop acting crazy. Yes I love you (I think...)


Help in Portland!!!

«1

Comments

  • Buy the steam books from the store here, and you will gain knowledge about these wonderful systems.
    Your pressuretrol should have cut off the burner before it got up to 8 psi.
    Most people here use Gorton #2’s, or big mouth main vents, so you probably need more main, (not radiator) venting.—NBC
    Intplm.delta T
  • Jamie Hall
    Jamie Hall Member Posts: 23,168
    Definitely more (or more likely, some) main venting, as @nicholas bonham-carter said. Further, the fact that your burner seems to run continuously but heat isn't getting to the radiators suggests that the pressuretrol -- and the boiler pressure gauge -- isn't sensing the actual boiler pressure.

    Can you post a picture of the boiler showing the pressuretrol and the pressure gauge, as well as perhaps an other few to show the front of the boiler with the controls and all? We may be able to make some more intelligent comments that way.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Intplm.delta T
  • acwagner
    acwagner Member Posts: 505
    Did everything work before the "local company" adjusted it? What did they do?
    Burnham IN5PVNI Boiler, Single Pipe with 290 EDR
    18 Ounce per Square Inch Gauge
    Time Delay Relay in Series with Thermostat
    Operating Pressure 0.3-0.5 Ounce per Square Inch

    Intplm.
  • rgargoum
    rgargoum Member Posts: 20



    This is my boiler.

    The superiority of the big mouth main valve is noted. I will invest in these as soon as possible.

    The heater hasn't worked well all season. I just bought the house in July, and I don't think there were issues with the heat before. In fact, the other tenants said they loved the heat in this house.

    The local serviceman said that he set the boiler back to factory settings.


  • rgargoum
    rgargoum Member Posts: 20


    Sorry for the poor quality images.
  • acwagner
    acwagner Member Posts: 505
    When you say it runs continuously, does the burner on the boiler continuously run and the thermostat is never satisfied?

    Or is the thermostat being satisfied before any radiators get hot?
    Burnham IN5PVNI Boiler, Single Pipe with 290 EDR
    18 Ounce per Square Inch Gauge
    Time Delay Relay in Series with Thermostat
    Operating Pressure 0.3-0.5 Ounce per Square Inch

  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    Are all the radiator valves open? Are the vents venting?
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rgargoum
    rgargoum Member Posts: 20
    edited November 2019
    Thanks for your responses!

    The thermostat is never satisfied.

    As for the vents, I'm not sure what they should be doing. All valves are open, but they demonstrate no activity.
    SeanBeans
  • acwagner
    acwagner Member Posts: 505
    I'd start by clocking your gas meter to see if the boiler is firing at its specified rate.

    Here's a site with some instructions:

    https://hvactechhangout.com/home/system-measurements/how-to-clock-a-gas-meter/

    If the boiler is continuously running, not building any pressure, not heating anything, not satisfying the thermostat, and not being shut down by any safety features, then my guess is the tech downfired the boiler to try to resolve your short cycling and screwed it up.
    Burnham IN5PVNI Boiler, Single Pipe with 290 EDR
    18 Ounce per Square Inch Gauge
    Time Delay Relay in Series with Thermostat
    Operating Pressure 0.3-0.5 Ounce per Square Inch

  • JUGHNE
    JUGHNE Member Posts: 11,042
    Is that a power burner with a fan? If so it would have pre-purge and post purge fan run times for every burn. Do you hear the burner actually firing or could the sound of the the fan only be leading you to believe you are firing.
    What do you have for a tstat, it could be short cycling the fire if adjusted for furnace forced air use, you want long cycles of maybe 1-2 per hour.
    Also you have a Cycleguard control that stops to check water level in the middle of the cycle.....most are replaced.
    B_Sloane
  • nde
    nde Member Posts: 86
    edited November 2019
    hey, I have the exact same burner for converted oil boiler. The riello is a good burner but ideally should be adjusted by riello certified tech. I had very similar problems with my system ultimately traced to small vaccuum vents (for coal boiler) on the mains. Trace the main piping to the point before it drops back down to the return piping. Is this where you set the new mains? This is where I found the small vaccuum vents. Had to remove them with a wrench and 4 ft piece of pipe slipped over wrench as they were completely rusted in. Once out I replaced with the big gorton 2s, they run approx 100/pop for them but well worth it. Once I swapped one onto each main, they warmed quickly and pressure dropped way off. You can also remove the rad vents by unscrewing/removing and this will quickly show you if steam is reaching them during a cycle but dont get burned! Sometimes rad vents get clogged with water and need to be taken off, shaken out, then reinstalled to allow them to purge air. You can also mount a cheap 0-3lb wika gauge or similar, I have that same blowdown and it should have an extra port that probably has a plug, you can remove that and mount the low pressure gauge there on a pigtail. May need to put a few elbows/pipe pieces to mount it above the waterline but easily found at any hardware store. Even my oversize boiler runs only 1-2 ounces during typical burn cycle so lbs means something is way off, probably air is trapped in the mains.
  • Jamie Hall
    Jamie Hall Member Posts: 23,168
    Well... at least the pressuretrol is set properly.

    The Ventrite 35 is a nice vent. While it's listed as a main vent, it really doesn't have the capacity needed (roughly a tenth of a Gorton #2). Which is what I would suggest you try for main venting -- one near the end of each steam main.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    bdwild
  • rgargoum
    rgargoum Member Posts: 20
    Thanks for all your help folks!

    In the mean-time, I have replaced the main vents with B&J Big-Mouth vents, and after the local expert adjusted my Riello burner, it's no longer acting up. It stays on until the thermostat is satisfied (other than a 1-minute break every 10 minutes for the cycleguard's low-water test).

    This has definitely improved the heating, with steam extending a much longer distance along the mains. Still, it seems that the home is being heated mostly by convection by heat rising from the basement as the pipes in the basement are not fully insulated.

    I am still a beginner in understanding what is normal for a steam system, and since it hasn't gotten REALLY cold in Southern Maine yet, but I still wonder if my system is working correctly. One of my tenants seems to think it is not working correctly, as his radiators are not as hot as he's used to (he came with the building when I bought it), though his apartment is warmed by plenty of radiant heat from the basement).

    My unit's radiators are only ever partly warm though they are maximally opened, and steam valves on the radiators never make any noise. I can get a whole radiator to heat up if I take the valve totally out, but still this takes forever (I thought steam was supposed to travel 40MPH!!!)

    I know that Dan Holohan would say that air isn't getting out. I just don't have the experience to figure out where to invest my energy and money.

    Things that come to mind:
    1. insulating the basement pipes (Is steam condensing before it gets to radiators?)
    2. All new steam valves on the radiator. I'm happy to do this as I know this is regular maintenance, but I have 20 radiators in this building$!$! and if I make this investment, I hope it fixes the problem
    3. Having a real expert troubleshoot my burner (Is my system under-fired?)
    4. Having a real expert evaluate and adjust the slope of the returns.

    I'm just puzzled because everything seemed to work great last year according to my tenants, and nothing has changed.

    Finally, I also just got my first heating bill of $400 for November. It's not even that cold yet!!!
  • rgargoum
    rgargoum Member Posts: 20
    BTW,

    I clocked my gas meter at 100,000 BTU/HR

    Again I have 16 6-fin radiators (about 3.5 x 1.5 x 0.5 feet each) and 4 2-fin radiators (one third the size of the bigger ones). I have a ton of exposed pipe in the basement.
  • kcopp
    kcopp Member Posts: 4,419
    Yes insulate your piping!
  • gfrbrookline
    gfrbrookline Member Posts: 753
    What vents do you have on your radiators?
  • rgargoum
    rgargoum Member Posts: 20
    1. Yes, I'm in the process of insulating.

    2. Radiator vents are a mis-mash

    Most are vent-rite #1, Eaton Yale & Towne No 1A
  • gfrbrookline
    gfrbrookline Member Posts: 753
    Also remember the goal is not to heat the radiator fully, you want to heat the living space. If the Tstat is satisfied before the radiator is fully heated and the rooms are heated evenly you don't have a problem, your system is working as it should.

    When you replaced the main vents with the Big Mouth's it let the mains fill correctly and the steam is now being distributed to all units evenly, this would explain your tenant's comment as he was probably over heating while other units/rooms were under heating. You need to do a temperature check in all of your rooms and will likely need to adjust your radiator venting to balance the rooms. I recommend using Ventrite #1 vents to do this, their adjustability make it very easy. https://www.patriot-supply.com/products/showitem.cfm/VENT_RITE_1
  • gfrbrookline
    gfrbrookline Member Posts: 753
    I just reread the thread, since you have 16 radiators all the same size I would install Hoffman 40's https://www.supplyhouse.com/Hoffman-401440-40-1-8-Angle-Steam-Radiator-Air-Valve on those and Gorton #4's https://www.supplyhouse.com/Gorton-G4A-Gorton-No4-Angle-Vapor-Equalizing-Valve-3525000-p on the smaller radiators.

    This should balance everything out.
  • rgargoum
    rgargoum Member Posts: 20
    Thanks for the advice!

    So the benefit of the Hoffman 40's is the price?

    And the benefit of the Ventrite 1's is the adjustability?

    Should I splurge for the Ventrites in order to help my tenants regulate their heat? There is only one thermostat in the whole building, and it's in my apartment.

  • mattmia2
    mattmia2 Member Posts: 9,574
    What is the boiler rated at, both BTU input and EDR of steam?
  • gfrbrookline
    gfrbrookline Member Posts: 753
    If your mains are vented correctly they should fill evenly and allow steam to be equally distributed to the radiators above.
    Since you have 16 radiators that are the same size you should be able to use the Hoffman 40's on all or them, the rising heat from the lower level will offset the time they take to vent the air out of the riser on the upper floor(s). If you have cold rooms you can add Ventrites to them.

    That being said to verify you have enough main venting, sorry if it is posted above ad I missed it, what diameter and how long are your mains? One Big Mouth on each may not be enough given the load. I have a similar load, unfortunately five different size radiators in six units, and have six Big Mouths and four Gorton #2's on the mains. It may sound excessive but it lets me run the system well below 1psi and cut my heating bill by 1/3rd. Paid me back in one heating season.
  • gfrbrookline
    gfrbrookline Member Posts: 753
    The Hoffman 40 is a very good quality vent, I am not suggesting it as a low market alternative to the Ventrite.

    As for your thermostat, I would recommend a Honeywell VisionPro 8000. It will allow you to place wireless sensors in your apartments that will average the building temperature. With a little finagling it will also let you validate any hot/cold complaints.
  • Jamie Hall
    Jamie Hall Member Posts: 23,168
    On the comment on tenants -- having dealt with them -- the question isn't what was it like last year (they don't remember, or at best selectively remember), the question is are they warm enough. You'll get there.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • gfrbrookline
    gfrbrookline Member Posts: 753
    @Jamie Hall agreed, that is also why I had second thoughts on the ventrite #1's and recommended the VisionPro. My tenants tend to fiddle with things that are adjustable.
  • The Honeywell VisionPro thermostat can use a remote temperature sensor, and therefore the main control can be in a secure area, accessible only to you. Replace the thermostat with the sensor, or choose a better location, and mount the control inside the boiler room.—NBC
  • nde
    nde Member Posts: 86
    Insulating the main pipes will help heat the rads faster, but in itself a bare main should not affect the warmth of each rad, it just takes a bit longer and wastes heat in the basement. Not the best time of year but you need to test each rad with vents out to see if they all receive heat close together. If so then just a matter of venting them proportional to where they are on the runs.

    I use hoffman 1as and gortons on the rads, both work well but hoffmans can click which annoys some people. What is nice about the 1as is you can dial them in but need to remove the cap and make sure line up correctly before tightening as there is some play there. The gortons work nice and quiet but are pricey, I find the gorton 5 to be a great all around vent even for 2nd floor vs using any 4s. The gorton 6 also work well if you have specific rads that are definitely slower than others.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    edited December 2019
    If the radiant load is close to the EDR output of the boiler, insulating the mains can help radiators that aren't heating well. I have a 9' long fin-tube radiator that doesn't heat all the way across. (It's just too damn big.) Before I started insulating my pipes, it barely heated at all, but every time I added a few feet of insulation, I gained a few inches of heat on the radiator. Now that everything's insulated, it heats a little over halfway (which is actually plenty for the room it's in).
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rgargoum
    rgargoum Member Posts: 20
    Thanks so much for your input!

    I'm glad to hear that things may be working as designed, as I am understanding that the radiators don't need to be hot all the way across and likely there was uneven heating last year with my downstairs tenants getting tons of heat.

    The house is comfortable, and I think adding the remote temp sensors and upgrading the thermostat will be a great update so that I can monitor different zones!

    If things are comfortable now, even in the rooms with the most distant radiators, do I even need to replace the vents?
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    rgargoum said:

    If things are comfortable now, even in the rooms with the most distant radiators, do I even need to replace the vents?

    I'm sure the folks who make the vents would appreciate it, but I'm not sure if anybody else would. :D

    Or, as @Jamie Hall said in another thread (where someone replaced all their vents and actually made things worse), "If it ain't broke, don't fix it."
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rgargoum
    rgargoum Member Posts: 20


    So I've been getting used to my system after having added B&J big mouths and not expecting the radiators to get overtly hot, and my home is warm.

    However, twice now I have come home to an overfilled boiler, with water leaking from one of the first floor radiators into the basement.

    In reviewing causes for an overfilled boiler, I am heading down these paths:

    1. clogged return
    2. system leak and improperly set automatic water refill (although my automatic water counter has not changed)

    Any other thoughts?

    I think I really need professional help, but I am not sure where to turn!!
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    This is something that often occurs when excessive amounts of water are forced into the system due to water contamination. The cause can be surging (rough boiling due to oil or grease on the surface of the water) or foaming, caused by additives or high pH. Flushing and skimming usually helps unless there's something in your tap water that's causing problems.

    If enough water gets driven out of the boiler, it triggers the LWCO, which calls to the autofill to restore the water level. Then, after the thermostat is satisfied and the boiler shuts down, the water trickles back from the piping and overfills the boiler.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rgargoum
    rgargoum Member Posts: 20
    If I don't see oil or grease at the top of my site-glass and if my site-glass is relatively stable (not surging), then where should I look? Should I still skim?

  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    Does the water level go down while the boiler is making steam?

    Do you see anything that looks like bubbles above the water line?

    Do you have any additives in your boiler water?

    One thing you can try is draining about a pint of your water into a pan and setting it on your stove and boiling it to see if it foams.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rgargoum
    rgargoum Member Posts: 20
    I'll have to mark the water level and watch it through a cycle, but I don't think it's changing much.

    No bubbles are present.

    I recently acquired the home, so I'm not sure about additives.

    I will do the boil test tomorrow.

    Thanks again for your help!!
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    Back in December you said, "There is only one thermostat in the whole building, and it's in my apartment". Is it in the coldest room in the house?

    As I was working on my system, I came across a comment on this web site about putting the thermostat in the coldest room, getting it satisfied, then adjusting the other rooms. It made a lot of sense to me.

    I did that and it made balancing easier. But, I was too lazy to move the thermostat to the coldest room (which had leftover wiring from previous work before I bought the house) and got the Honeywell wireless thermostat and added the wifi device, so I can monitor and control it from an app. It isn't cheap ($300), but now I don't have to go into an apartment to turn up the heat, I just use my cell phone. And I can relocate it if I have to without running wiring. Worth the cost already.

    I think it has the capability to be locked, so a tenant can't change the setting, but I haven't looked into it.

  • dopey27177
    dopey27177 Member Posts: 887
    You need to slow down a bit. Do not get get hooked on your problems are radiator vents. Replacing all your vent valves is costly and don't save money.

    You have an extremely large amount of steam main and piping that has no insulation on it. It also appears you only have dry returns. Excessive condensate is built up n your piping system because the steam condenses to water and much of it is stored in the piping before it gets back to the boiler.

    There is a thing called time lag. Time lag is how long the stored water in the system gets back to the boiler. Water flowing back to the boiler lows at about four fee per second. It appears that the total amount of condensed water from the radiators and the steam pipe returning slowly causes the boiler to use or fill with fresh make up water there by causing an over fill.

    If you had a wet return system this condition would probably not exist.

    If you insulate the steam main you would limit the amount condensate formed in the steam main and increase the amount of steam supplied to the radiators quicker.

    Additionally, you save about 20% of the BTUs used to heat the steam main.

    Vent valve balancing will work better if once the steam main is insulated.

    The insulated steam will cut down burner run time therefor lowering the cost of fuel. The insulation will act like a government bond saving you money on fuel year after year.

    Enclosed is an excerpt from my book on energy savings for insulated piping verses no insulation.

    This was done in a factory that was converted to apartments in Manhattan.

    Jake

  • rgargoum
    rgargoum Member Posts: 20
    edited February 2020
    Wow!!

    I purchased "The Lost Art" and read the relevant chapters last week. I have a single boiler with a manifold serving 4 one-pipe mains. The first-floor apartments have shorter dry returns and longer risers than the second-floor apartments.

    I understand the system a little better, but I mostly now understand that this is truly is an art, an art which necessitates constant attention.

    I am as willing as anyone to invest in a system to make it function better, but I'm afraid that I'll be investing in things that don't necessarily make my system function better, or make it function worse. So far I've invested in bigger main vents (4 big-mouth main vents, at the ends of my returns, and insulation for my some of my previously un-insulated mains).

    I am delaying in doing a couple of things:
    1. replacing all the vents on all the radiators in the house
    2. insulating all my basement pipes

    I think I truly need an expert and a whole-system evaluation.

    Why am I delaying?

    1. I have delayed insulating some of the downstairs piping. One reason is that I wondered if the people who installed my new boiler calculated the un-insulated pipe into the overall heating equation. I seem to have read some things to this effect on the wall and in "The lost art." If it was calculated into the heating load of the house for all the basement pipes to be un-insulated, wouldn't insulating the pipes set me up with an over-fired boiler and potentially a problem with short-cycling?
    2. I was having a problem of the boiler spontaneously over filling throughout the winter, but the system was at least stable for 2-3 weeks (not sure why), so I didn't want to change anything.

    UNTIL LAST NIGHT!!!

    Again I came home to whistling vents on the radiators in my second-floor apartment, and went to the basement to find the water line way over the sight-glass, water spilled all over the basement floor, rusty discolorations at the lips of two of my big-mouths, and the crappy pressure gauge reading 5 lbs of pressure.

    This time I emptied at least 15 gallons from the boiler, but the line is still way above the sight-glass and the pressure hasn't budged.

    I am truly baffled as to where this water comes from, and therefore scared of draining any more off. My automatic electric feeder stays at the same number where it has been for weeks, 051. (What is this 051 gallons? liters? hundreds of gallons? I am only confused because if I removed 15 gallons from my system, where did it come from? why is this number the same?

    I am so puzzled.

    1. Where is this extra water coming from? Is it from time-lag as dopey suggests?
    2. Why doesn't my electric feeder's number change?
    3. Why does my pressuretrol allow the pressure to get up to 5 psi? (It's set to cut-in at 0.5 with a diff of 1)
    4. What do I do next?
    5. Why does this happen? Was it because I lowered my thermostat to 60 for half a day when I wanted to open the windows for a few minutes to air out the apartment? What's going on???

    Baby, I want things to work, but you have to stop acting crazy. Yes I love you (I think...)


    Help in Portland!!!
  • rgargoum
    rgargoum Member Posts: 20
    edited February 2020


    This is my boiler right now.

    Water all over the floor, rust spots at the bottom of 2 big-mouth mains, water level WAYY over the sight glass, pressure gauge at 5 psi, with pressuretrol set at 0.5 with a diff of 1.

    This is after I removed 15 gallons of water last night. I'm afraid to remove more because I don't know what's going on!!!
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited February 2020
    Edit: First pass: What comes to my mind is that your pressure was possibly at around 5psi (due to your pressure gauge reading and the whistling vents). This would push the water back up the wet returns, up the condensation drop pipes and out of your main vents (this apparently happened because of all the water on your floor).

    This tells me your pressuretrol is faulty, or more likely, the pigtail it's hooked to is clogged so your pressuretrol isn't seeing the correct pressure.

    Part of annual maintenance should be to clean the pigtail.

    EDIT: (2nd pass) Wait, your water level is way above the sight glass even with the boiler off? OK then your auto feeder either failed open or it saw your water level is low for some reason. Your auto feeder only can report the numbers it knows about. If the valve got stuck open, then the "brain" won't know that more water is leaking out. For now you can disable the autofeed, drain to the correct water level, and monitor the heating cycles to see what is going on otherwise.

    You should have a licensed service organization you trust if multiple families are relying on this system running right (which it sounds like they are). It's one thing to tinker in one's own basement (which I do all the time), but this is a different situation.

    Regarding your hesitation to insulate the mains. Don't. So what if your boiler is too big? If so, it is already too big, you are just masking it by pumping heat into the basement, wasting fuel and $$$. You are concerned about "short cycling", but I wouldn't be. The boiler doesn't care. If you have dramatically short cycles due to pressure that really bother you, there are relatively simple fixes for that. But step one: insulate the mains (once your overpressure is solved haha)
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el