Best Of

If it was me I'd replace the boiler myself, others on this site have, and I believe they are glad they did. It seems your contractors only want to do a mediocre job. Probably the hardest part is getting the new boiler into the basement. Although it actually seems that the hardest part is for some contractors to do a good installation job.

If you prefer to not do the work yourself, I guess keep getting estimates until you get one you like without a lot of coaching. Has any contractor measured the radiators ?

I'd match the boiler (Square Feet) to the EDR. (Assuming the EDR survey is accurate) As an example, my boiler could run for hours (if needed) and the pressure never gets to 2 Inches of water column (0.072 PSIG). It is slightly undersized, yet heats the house just fine. No extra pressure during a recovery from a setback.

Your near boiler piping is not correct. So it should be corrected, a new boiler install is the perfect time to get it done.

I would not reward Burnham with another purchase. Maybe 29 years is good run for a Burnham. I believe my old boiler is over 50.

The drips at the end of the mains should be individual pipes until well under the boiler's water line then connected into the wet return, to isolate each main from the other.

Since you are using Big Mouths, run the longer main with minimal or no vent restriction, a custom orifice can be easily made from a pipe plug and added the threaded vent of the Big Mouth on the shorter main. This way the steam gets to the end of each main at about the same time.

I'd probably get the chimney repaired / relined for quiet boiler operation and maybe change the orientation of the boiler to minimize the flew pipe length.

I would spray the threads with "Kroil" or any penetrating oil numerous times over a few days before you try to remove that pigtail. Let the penetrating oil sit for hours to allow it to do it's magic. Then use a 6" or 8" Ridgid pipe wrench, putting it as close to the low water control as possible to reduce the chance of breaking the pigtail. Try turning the pigtail just slightly CW as if you are trying to tighten it before you try to remove it. The last torque that pigtail saw was when it was installed so the resistance to turn will be the least when turning it CW as if still tightening it. When you get it out, replace it with a brass pigtail and use Permatex anti seize lubricant.

The farther you grab it from where it screws into the LWCO the more chance it will break off.