Best Of
Re: Leaking new vents?
Yes your boiler is rated for 391sqft but that is to be compared directly to your standing radiation, not the radiators + piping. The boiler rating already accounts for the piping estimate. So you are almost 50% oversized with all your radiators open. In my opinion you would be better off with slowing some of the radiators down getting a little more length out of a cycle to give the house a chance to heat up before all the radiators are filled and you start cycling on pressure.
Re: undersink water heater for dishwasher?
I would probably go with Bosch. I've heard that Miele is good too but i'd need corroboration on that. I have a bosch that is about 25 years old. I've had to repair or replace the water vavle a couple times and had to install a beefier relay for the heater. Oh and i had to get a slavaged rack because the coating was pretty easily damaged. If I had more space/less stuff i'd probably get a hobart built kitchenaid.

Re: Leaking new vents?
So true, and I tried to word my post not to infer that your suggestion isn't a good one. I just wanted to mention that there are considerations that must be, eh, considered. When manufacturers market a boiler with different burner configurations they have done that considering for you and are confident that the option is worthy of their "good name".
Re: What I think
The dystopia we are in is Brazil. I don't seem to recall them finding a solution at the end.

Re: What I think
Things with mechanical or electromechanical or electronic or microprocessor controls all fundamentally works the same. If you have to put a lot of effort in to understanding how one manufacturer's system works you don't understand the basics.
I don't think you're going to get many people to sign up for night school while working all day when there are lots of jobs that don't require that. You need to fix that model.
You need to understand math and chemistry and physics but the middle/high shop class curriculum doesn't teach that. You need to figure out how to teach it to the people that don't understand it the way we've been teaching it for 100 years. And you need to find people willing to do it for less than the cost of living.

Re: What I think
I'm reading a book now, "Reader, Come Home". The author tells how learning to read rewires our brain in very fundamental ways, and that the modern "digital" world is changing that, again at a fundamental level.
Scary to think that we're raising up kids who, not just don't think like us, but can't.

Re: New Century House with Two Pipe Steam - Questions
Actually I think that one with the nipples and ells is maybe some sort of humidifier and those are connected to the trough on top.

Re: Uninsulated steam main is heating up basement. Is that so bad?
If your basement is 68°, don't insulate or you'll have to install a radiator. If your mains are all behind walls, that's probably insulation enough, but you might be losing heat to the outdoors on outside walls. If that's the case I'd say insulate the walls, not the pipes.
Re: What I think
One of my neighbors is having their kitchen remodeled and adding a half bath - no permit. She said I could come by and take a look at their work now and then to make sure at least the plumbing looked OK and when I did, I saw that there were some issues: copper x male adapters into 100 year old galvanized pipe, 1-1/2" p-traps on showers, leaving original cast iron drains in the wall……I suggested some corrections to the lead guy and they refused to do them and they have banned me from the job; I'm a nosy neighbor. I told the owner that she might have problems in the future and she said, "Just let it go."
To the current topic, many - most? - homeowners really don't know the right way to approach suggestions and work done by the guy that knocks on their door and works on their house. They want to trust them. Do they really need a new boiler or is it just a tripped spill switch. People know how to use computers really well, but not the workings of their house.
Re: What I think
used to be the farm kids learned all about keeping basic machinery working. Now John Deere has them locked out of working on their own equipment. Elon with his massive AI push will fix everything, no need to worry.
