Residential boiler lifespan?

[wooson]

I have 20+ year old small boiler that has spent most of its life supporting a mostly wood burning stove. I've cleaned it and changed electrodes, nozzle and oil filter every Fall. I burn about 200 gallons a year. We've lived here 50 years and will probably be leaving in the next five. It's a very old house requiring more than I can deliver much longer. So I'm considering replacing the boiler. I updated the Becket burner a few years ago and it has had no issues heating the two story house when it gets into the colder temps or if I let the wood stove go out. It has no noises. Radiators and copper lines are probably from the 1930's when all the documents I could find regarding putting indoor plumbing occurred. It has water heater coil, I turn the call for heat settings down so it barely runs in warmer weather and just use electric hot water year round. It keeps the humidity down in the basement.
I guess I'm looking for someone to say the limited use over the last 20 something years means something in its longevity. Thanks for reading, John

 

[Fitter30]

Over years has much fresh water been added to to boiler from leaks or general maintenance? Reason for asking with fresh water it brings with it oxygen. With a lot of make up that oxygen is bad for the system creating rust and can eat up boiler sections. If boiler has seen a lot of make, take a look at the refractory looking for cracks and broken pieces and the pump. Pump old B&G if its the red open motor and coupling. The rubber motor mounts go bad and coupling wears out they still might carry parts for them. I'd just run it unless your thinking it might help the sale of the house.

 

[Sponsor]

 

[wooson]

I only opened on time to add a 6" section of 1" copper tubing about four years ago. It was in a spot where I had to drain about a third of the system. Otherwise it's just when I vent air every Fall from the second floor radiators. Maybe a few gallons from the pipe mod? I'll check the inside of the firebox when I change the nozzle, etc. The pump is a fairly newer model. I swapped the burner 6-7 years ago with a newer burner. It was slightly used but looked hardly used. I have a couple spare burners and other parts around. Thank you for the very interesting information.