Best Of
Steam Heat - Music to my ears
For most members here this is old news but for some of us younger whippersnappers we may not have been aware of these. At the inevitable moment in any conversation with friends these days where steam heat comes up one of my friends last night (one that has more of a musical artsy background than myself) immediately mentioned "Steam Heat" from the 1954 Broadway musical Pajama Game and sent me a link. Other than there pressure needing a little reduction I found it quite entertaining.
(I did do a search and noticed that credit is due to Patrick McGrath in Dec 2009 for introducing this to the forum, 5 yrs before my time here)
The 1954 Broadway and the 1957 musical version links below: Enjoy!
Re: Direct to load mini buffer
5/16" refrigeration tubing is ideal for the common 6mm (.240) sensors being used these days. In some cases you want multiple sensors in one port. I use a male adapter and 97/3 solder to assemble them.

Re: The Green Knob
we discontinued the repair cartridge for the small Caleffi thermostatic valves as it didn’t always solve the problem. The problem was the scaled bodies.
So we offer the valve body and cartridge without the fittings as an option to buying a complete valve. It saves a few bucks,

Re: Two Nest tstats for gas-fired steam boiler with tankless loop - failed install
UPDATE
My contractor replaced the Taco and transformer to bring the system up to operations. We decided that the best way to allow the Nest to control the steam heat would be to install a separate transformer/relay as some have explained.
Doing so is beyond my skill set. The cost of paying a professional to do it is too high given the reasons I had for wanting it. Rewiring it as some have proposed would cost less but would make the connections non-standard, creating challenges for future professionals. So I'm using the old thermostat.
Thank you all for your comments and discussion. I do appreciate your time and expertise.

Direct to load mini buffer
I have a 20 gallon tank on my A2WHP now. With one zone I don't really need much or any buffer.
This Siegenthaler suggestion uses a 5 gallon capacity tank, gives me the direct piping with a Discal on the top supply, still engages some tank on the return. I'll add a magnet in a well on the bottom also.
A modified Harbor Freight air tank with some Caleffi parts welded in. I have a choice of connections tailpieces with the threaded G thread adapters welded in.
Taking it to a professional welder for a leak-proof tank on the first try :) Then blast and powder coating.

Re: Steam heating system. Leaking pipe connection
Thank you all for the responses. My plan A is to replace the bad pipes with exactly the same sizes and lengths. It will be in a couple weeks. And I may get back here if something goes wrong.
Thanks again for your help.
Re: Replacing Taco 007 with a variable circulator
Thanks Dave !
Sourced on-line as Local distributors don't seem to stock much here for some reason.
Current Knight
We just finished this boiler replacement job. The 30 yr. old Laars Mini-Therm started leaking and replaced it with this floor-mounted Lochinvar. It's not my prettiest job, but - surprisingly - we had no leaks. Well, there was one and it was at the factory brazing joint for the tridicator and - surprisingly - it went away.