The fact other properties have chewed up sidewalk isn't a sound legal argument either.

The land that this property was built on was approved based upon the capability of the land to support the septic needs of a specified-sized property. 

Do you have property managers and contractors who your clients have been using for over a year successfully?

If they over-promise and under-deliver, transfer the next property to a different PM.

The tenant supposedly had complained for months to the property manager that the furnace was not working.

I am assuming by your post that you are financially invested and own the property. 

I'm a Realtor with a couple properties listed in Boise, ID and a neighboring town for my investor/client that are currently rented as co-living or rent-by-the-room and getting killer income. (7.3% - 9.5% Cap rate) So far, every inquiry has been baffled by the concept of co-living or rent-by-the-room and immediately ask if they're being run as a halfway-house (which they are not).

Using the equity I built up in that property I got a HELOC and started investing remotely out of state.

You can do the outreach yourself to connect with off market properties or connect with people who can find them(agent, wholesaler).

Find a property that is listed on the MLS.2.