Gas Boiler/ Stone foundation dehumidifier Comments Please

[Tes Liu]

Hi everyone! I am hoping to hear some input from you experienced folks on this subject. I am making offers on two different properties, both over 100 years old. One is a 7unit (2b/1b) apartment house with a whole house gas boiler and the other is a small row house with stone foundation that seems damp. The numbers for both buildings are good based on the rental analysis on BP. 

The gas boiler scares me a little even though it's supposedly fully functioning. I don't know how expensive the upkeep or replacement is for something like that. It's making good income but all utilities are paid by the owner, no separate meters. It will need a rubber roof re-coating next year or two. The building itself seems to be in good condition and completely occupied. Love to hear some input from anyone who's had this kind of experience. I am on the fence, should I pass?

The small row house 2 story 2b/1b is also nice in general but the stone foundation and dirt floor is something I have no experience with. The dirt floor seems damp. But this is a middle unit with two other homes on both sides. It fronts directly on the sidewalk in front of the house with one basement window visible from the street. There is only the back side that has direct exposure to the ground. My realtor says to use an industrial dehumidifier, but the waterproofing company says it needs french drain and concrete floor with waterproof wall covers. Of course the second option is 5x more costly and perhaps not worth the value of the house. Has anyone any experience with running the dehumidifier successfully as a long term solution. Of course, the concern is mold and the liability associated with it. It is newly rehabbed and with tenants. I did not notice any bad smells. I know a lot of the older stone buildings in the Northeast have stone foundations, and maybe this is a very common issue that I shouldn't get too uptight about?