All in all I just don't appreciate how this was managed from beginning to end and I wouldn't recommend risking it unless he lengthens the guarantee, shortens the training/setup time, and gets an actual support staff......that is customer oriented!

@Lane Cooper - In terms of relatively low risk vs. high reward, I have yet to find a single better investment than doing a house hack. 

If you can buy it for 10-20% if it’s value and have a high tolerance for risk, go for it.  

Of course, you better be sure that you're getting that mortgage otherwise you are at risk to lose your deposit if financing falls through. 

@Melissa Mendoza, it depends on the level of risk you want to take as an investor. 

The landlord has a duty to mitigate the risk and actively seek a new tenant.

It depends on your risk tolerance, really. 

In addition to what Wayne said the seller will have to pay imputed interest gain and will make almost or maybe ZERO cash flow if he takes this to an accountant .. or anyone who knows anything about these seller carry backs your going to have push back I suspect unless your paying WAY over market.I have sold a lot of my OREO over the years with ZERO % owner carry but always set them up short term.. 30 months 40 months that sort of thing ..

Idea behind replacing the oil furnace is avoid having the copper lines risking freezing during very cold winters, not having to worry about oil delivery and possible spills and overall it simplifies maintenance of the unit and make it more appealing with central cooling and heating.

Had I known there was a tank I would have a) not purchased the property (I passed on several properties because I didn't want to deal with an oil tank) b) had the owners remove it at their expense or c) would have asked for a significantly discounted purchase price to account for the risk.