Is my Weil-McLain EGH-95 dead? Replacement advice requested.

vaporvac

You seem to have more radiation per sq ft than I. Your house seems similar to @Jamie Hall 's in size, but I don't recall his edr. Of course, he's in the NE as well.
I can't comment on the twinning aspect or reliance on an atmospheric vs. a power burner. It's very little more...but they do need to know how to install the power burner and use a combustion analyzer. In any case, you should push for a multi-stage burner as @Dave0176 suggests. It saves some serious money and you'll be amazed at how much NG a large house can blow through.
@KC_Jones point may still be correct. I don't know how the 1" pipe compares to the 3/4", but the pipe size does determine the max edr. Therefore, one can have a huge emitter, but it will only emit as much as the pipe leading to it allows.

KC_Jones

A 1" pipe maximum is 104 on gravity return. In reality at low vapor pressures probably lower than that. It depends on system design and what kind of pressure drop they anticipated etc. It's not totally cut and dry, but from what I am seeing not sure if I would size the boiler to those emitters. I can't remember where I read it (most likely one of Dan's books), but I recall some systems had the emitters oversized on purpose. This was to ensure that all steam was condensed before it got to the return piping. Is it possible this system was designed like that? I seem to recall something like 80% of the actual emitter size was for heating. 80% of your 120 EDR would be 96 which is within the range of 1" pipe. Just another thought.

Fred

If it were me. I'd base the EDR of those radiators on the capacity of the feed pipe and not the size of the radiator. 1" pipe is the limiting factor here.

ChrisJ

Fred said:

If it were me. I'd base the EDR of those radiators on the capacity of the feed pipe and not the size of the radiator. 1" pipe is the limiting factor here.

Maybe, maybe not.
I have an 1 1/4" feeding a 60sqft rad and I promise you it can fill completely and not hammer.

Depends on the pitch of the pipe as well as length and what fittings there are. Under perfect conditions I'm sure it can exceed the norm by quite a bit.

Fred

ChrisJ said:

Fred said:

If it were me. I'd base the EDR of those radiators on the capacity of the feed pipe and not the size of the radiator. 1" pipe is the limiting factor here.

Maybe, maybe not.
I have an 1 1/4" feeding a 60sqft rad and I promise you it can fill completely and not hammer.

Depends on the pitch of the pipe as well as length and what fittings there are. Under perfect conditions I'm sure it can exceed the norm by quite a bit.

I would certainly expect a 1-1/4" pipe to easily fill a 60 EDR radiator. I think this poster is talking about a 1" pipe and a rad somewhere between 120 and 156 EDR, unless I'm misunderstanding what's been said in this string. In this case I'd go with the rated capacity of the pipe and I think I'd be closer to accurate than using the rad capacity.

KC_Jones

I wonder how this project has progressed?

hituw2x4

I am eager to see the projects progression too.

Fred

As am I !!

Steamhead

Somehow I missed this earlier.

Vapor systems, such as your Dunham, were the Cadillac of heating in their day, and are still some of the best out there. With proper care, this system will outlast us.

I'll be interested in the outcome here too.