Steam boiler condition inspection???

Guys,
I have a question regarding the condition of a steam boiler. We purchased an OLD house in Feb 2015 with a oil/steam boiler (Burnham MST288). The previous owner was an elder woman who didn't know how to care for the system. In the past year, I:

-Replaced oil tank gauge, it was broken (not really important)
-Replaced the pigtail.
-Re-Calibrated the pressuretrol for 2 PSI cut out, ~.5 cut in.
-added a 0-5psi gauge.
-Replaced one of two malfunctioning main vents with a gorton #2.
-Replaced various malfunctioning air vents @ the radiators.

The house has two mains, one main vent is stuck completely closed as of today (since we bought the house). The other main vent, at the time of closing, was pissing some steam out continuously for who knows how long. This resulted in TONS of feed water being constantly added to the system. The bushing was completely rusted, and I spent hours with a hacksaw blade carefully cutting so that I can get something to thread the new vent on. As stated above, this vent was replaced with a gorton as of Sept. 2015, and is working fine. This is why I don't want to touch the second main vent until it gets warm, don't want to open up a can of worms.


I did a little EDR calculation in another forum (given the existing radiators) and found that the boiler was vastly oversized. When the thermostat calls for heat, the boiler will cycle 45 seconds on, ~2 min off continuously.


In the near future, I plan to:
-Convert from oil to gas and have oil tank removed.
-Add hydronic heating to the basement, attic (unfinished), and extension at the rear of the house (smallish room, 20' x 10'). I'll do this via. condensate loop/heat exchanger.


BECAUSE of the continuous feed of water, I want to know if there's a way to inspect the condition of the boiler. How much life is left? Is it worth converting this to gas via just replacing the burner?? Or is it so shot that I might as well replace the entire unit?

(another issue for another thread, really) I'm guessing that extra capacity to the HW condensate loop wouldn't help with the short cycling/oversize issue?

Any comments truly appreciated. Thanks guys.

 

If there is not a water meter to determine how much water was added I feel it should be OK. This is a 3 pass steam boiler and will tank a little abuse better.
Normally she was not adding as much water on a steam leak as it would have for a water leak.

 

The feed meter reads 688 ... Although, I don't know if this was reset when the boiler was installed..... maybe there was some carryover? I don't know.