As I mentioned above, there is limited data available here in which to frame the numbers you did provide (the water/sewer alone could be another $5K/yr) and we know nothing of the economic vacancy, tenant population, asset condition/obsolescence, level of performance or room for improvement.You should be underwriting a property like this to (M)IRR (with a time horizon to your exit) and weight the cash component of the return based upon the nature of the property and its location.   

The nature of our business makes it imperative that we have happy, satisfied clients who will bring us repeat business and referrals.

These tanks, and direct vent gas furnaces/boilers, can be plumbed directly through the side of the building (foundation wall, sill plate, etc) provide the exhaust exists the required distance from an operable window, door, or other air intake.From an energy efficiency stand-point, direct vented fixtures are preferable as they are not taking their supply of combustion air from the conditioned space of the building (are you have already heated), causing colder, external air to be drawn into the building.Additionally, as Pat has pointed out, direct vented fixtures reduce the risk of natural gas/propane or CO being drawn back into the conditioned space of the home. 

This business is a little like professional sports in that some people just have natural talent for it and others don't.  

I am a natural problem solver and would love to help those who can give me advice.    

I consider my conservative nature and commitment to doing much of my own work as an asset. 

In a long term lease of this nature getting to value is only part of the equation.

The nature of the business has changed so much over the past 8 years since I started, that only those who are smart and savy enough (and well capitalized) to adapt and change to evolving market conditions are still around (and those that have treated their clients with their clients interest in front of their own).  

I think my goal is to create sufficient enough cash flow that allows me to first supplement my income, then leave the 9-5 grind altogether, but that could change as I delve deeper into each topic. 

He was living there and decided he wanted to keep it in the family for sentimental reasons...I'm not sure why he didn't assume the loan or something to that nature after the passing??