Most of the people use heat treatment, as steam cleaning process can work to kill off various types of fleas and other infestation in the house also.But, make sure to make a good plan to get rid of fleas.

Reminds me of the one we bought in '87 from an old hoarder who literally heated cans of food on the electric stove rings.

They will often be between 50 to 60% when roof, windows, water heaters, heating and air,etc. starts reaching end of life expectancy and has to be repaired to extend shelf life or fully replaced.Many times some brokers do a ( if buyers don't ask then don't tell ) kind of thing to get stuff closed and make their money.

New heating unit and hot water tank.

One point I disagree with- he mentioned a building with heating costs of $3,000/yr(I think it was oil baseboard, and the owner paid the heating bill.)

I am accounting $4900 for replacing the heat pump as it is quite old and it needs all appliances.

Ensure that your homes are clean, have fresh paint jobs, no funny smells, and have electricity/heat.

The old houses in Baltimore, 100 years in your case, can need substantial work to replace very dated wiring, plumbing and heating systems.

@hat materials do you use for the heat resistance to adhere tile to? 

The heating system is this old drum barrel & presumably an ancient forced hot air system.