Piped wrong

This looks like the installer of that boiler just copied the piping arrangement of the old coal boiler that was removed. Left riser to one main and the Right riser to the other main. And that may actually work for many years. I guessing without the equalizer, there is a check valve on the wet return somewhere.

But since you posted this in Chimneys and Flues, the first thing I looked at was the water heater and the gas boiler venting connection to the chimney. That looks fine too.

So they want a price for an replacement boiler without allowing you to calculate the radiation EDR? I would answer that TEXT with " A lot " but that could change when I do some calculations after the onsite inspection. Then it could change to "Reasonable". Let me know how you want me to proceed.

Count on a complete new Steam header.$$$$$....you're inheriting THEIR problem. Bring it up to YOUR standards because YOU will be married to this once the first wrench 🔧 touches THEIR pipes. Mad Dog