Old boiler system

Had a few questions pertaining to an old boiler.

My clients were very knowledgeable and understand about the asbestos coverings and that it was an old system. They planned on replacing in a year or two. They wanted to update the windows, add insulation and do some other updates first.

There boiler specialist stated that new boilers are not that much more efficient than this old one. This was a hot water boiler with circulator pump and radiator distribution, 2 level house.

So my first question is: Is that true??

Second question is on the venting system. I have never seen one like this,
Anyone care to educate me? The cast iron ball on the top seemed to act like a damper. The open pipe at the bottom of the vent seems to be for drafting.


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Don’t have the answers to your questions, but what I’ve seen done with this type of system is a heat-pump has been added and the original boiler system is used as a supplemental heating source (emergency heat).

I also do not have your answers, but this may help you out…


This boiler is probably 40% efficient. A new boiler can be 90+% efficient. I would replace it asap