I think he either removed the old mount completely or was in a process of adding a new cheaper mount which obviously had different configuration so he had to patch the wall. he is really a type of a person that will slip a dishonesty here and there and I experienced it many times. he would turn the AC to 67 when it was 100 outside and after unit would malfunction would change back to 72 and claim the unit is bad. he would do it when he would go on a trip which he did often is summer. now that he moved out the thermostat is on 73 and it is 100 outside and there is no issues at all. he also had his girlfriend live with him although he claimed he was the only one. he was always very particular about 24 hours notice that is how I know he was doing something he wasn’t supposed to. he is definitely dishonest but he was paying on time and relatively clean. 

If your offering the unit as you the landlord is paying for the gas, then I don't think it's reasonable to cap temp on the thermostat.   

ZulfCheck Chicago Controls...they offer temp limiting and auto set ba k thermostats.

Mine can set door codes, message (or call) guests, schedule cleaners, adjust the thermostat, monitor my cameras, & call a plumber just as easily as a local PM can, for 1% of the costI wrote much more about leveraging offshore assistants in this post here.

They found out that the thermostat wiring was not installed properly and there were a bunch of other things that should have been replaced but weren't and it's not up to code.

Can you get a smart thermostat installed?

Guesty for Hosts, Zapier, Sign Now, Ring, Smartthings Hub with RBOYS Rental Lock Automator, Sensi Wifi Thermostats, Hostfully Guidebooks

Make sure the thermostat is actually set to 60* and not left higher than that by an agent.

Will get Outdoor cameras & remote thermostats.

Has anybody used thermostatic radiator valves to save money in old apartment buildings heated with steam radiators?