@Caleb Heimsoth The maintenance guy brought the HVAC guy with him and they confirmed that the central isn't working or installed properly.

. :) You could find a couple cards with zero percent balance transfer offers and move the balances to them to stop the interest charges.

They seem to be doing fine as they have managed to keep a balance of about $6k in their bank accounts but would I consider them very risky and I don't think they can afford paying $2,200 rent without facing financial hardship.

Sometimes if the Tax Claim Bureau is of a mind, they MAY negate the sale, give the bidder back their bid price and auction off the property later with proper notice. 

I copied this from a search on real estate ROE:Return on Equity (ROE) ratio calculates the amount of return generated in a particular year on the total amount of equity invested (or trapped) in a property.The amount invested (or denominator) is calculated as the initial investment (down payment) plus the entire increase in net property’s appreciation and the entire decrease in outstanding loan balance incurred prior to the year the ratio is being calculated.Cash-on-Cash Return is a similar calculation, but since the two draw backs of the traditional Cash-on-Cash Return are that property appreciation and principal debt payments are not factored into the formula, Return on Equity adds these two components to the traditional Cash-on-Cash Return calculation.A property’s net equity increase is calculated by determining what the “Net Sale Proceeds after Taxes” would be at the beginning of a year, and then again at the end of the year.

Lots of questions here so if you can provide other details that will help me guide you properly.

I'll have to take photos tomorrow to properly illustrate.The neighbor also said that the mainline water pipe had several leaks in the past and has pictures to prove it.

You can see if the seller has been patching and fixing with cheap and improper repairs to suck out all the cash flow  instead of properly maintaining the asset during ownership.

I thought I had selected the proper forum on my phone while writing this.

Unfortunately, marketing is not really the top skill to be great at locating good properties, buying them properly, renovating them to at or above retail standards eliminating deferred maintenance and then acquiring quality, long-term residents and managing them properly.