They should be able to locate on the surface where the issue is, so that you can see if its where work was being done on their property and also they should be able to put a camera down the pipe to see what kind of issue there is.

Imagine collecting rents in bulletproof vests and you got to carry a gun...Imagine fixing a property up...securing it with steel doors, putting security cameras but the security cameras get stolen and even the steel doors get busted and stolen...Imagine dealing with renters who know the system and know how to live rent-free...If you can imagine all that...that is having a rental property in the war zone.Listen to my podcast: http://Biggerpockets.com/show65

Do you already have a front door camera?

The company quoted me $1200 which included a camera inspection afterwards. 

But then I had nightmare's of Holmes on Homes showing up at MY house with TV cameras and chose to go with 2 systems!

It required a hefty $15k camera inspection both before and after the cabling, just to ensure we weren't inadvertently wrecking any existing pipes or sewers.

All you can do is set up a camera at the gate that detects motion and watch it.

Lessons learned--always install security cameras on closing day if the property will be vacant for a while.

I travel a lot for my W2 income so being a full time PM is out of the question but at the least I can help out by video chatting with you for virtual tours, using my 360 camera to build a quick tour, or verifying contractors are actually showing up for work.Let me know if there is anything I can do.

Out in a security camera system at the gate.