So many properties out there may seem viable at first glance but the truth is all the juice has been squeezed from the lemon. 

If you opt for electric, the HVAC techs might not think like an electrician wherein the electrician will probably have to, 1) establish a new circuit with breakers rated for the furnace; 2), run higher gauge wires and/or piping to handle more juice that the electric furnace will require.

I don't have linkden ( well I have it but have not been on the site in years)... real estate is belly to belly...

Like Deanna suggested, have some portable air conditioners on hand for such emergencies.Last year we had to replace two HVAC units; course they went belly up in the middle of summer. 

That's the guy that wants you to default so he'll make more money than he would if you just paid him back the juice on the loan.Add on the risk of running afoul of any possible local or state lending rules (Like possible ATR (Ability to Repay) rules that some agency may place on him or you) and you are just layering risk upon risk.

I don't think the juice would be worth the squeeze on this one.  

He needs "belly to belly" discussion at this point and don't tell him it's your first REI. ;-) Keep in mind that he may have a project in mind that requires the funds from selling this for cash. 

Honestly, doing the math based upon my didactic background in business finance, there is no way I can take over the notes he has on the place (his suggestion to avoid banks and inspectors), cover operational costs (variable and fixed), maintain the known issues and repair the (recently) discovered issues without being either behind every month on the loan or going belly up.

I plan to do this because I have a very strong and stable W2 income stream where I can stomach the expenses if tenant goes belly up.

@Debbie Rumsey I will always make myself open to people that want to buy me a mid-day smoothie at the Jamba Juice in La Costa ;-)  I do think that @Justin R. offers some quality perspective for where you're at.