Joshua, Attic fans are simply a fan with a thermostat that cycles it on when the attic temperature reaches a specified temperature.

Make sure you have control of the thermostat or your tenants will turn it up to 90 all winter since they aren’t paying for it.

More reference: http://www.appliancepartspros.com/questions-for-ge-oven-thermostat-assembly-wb20k8-ap2623073.html

I am trying to find a thermostat with a pin code that needs to be entered in order to adjust the temp.

One advantage is each room has its own thermostat so you can turn a room off if you arent in it (ie bathroom)

Also make sure thermostat and appliances are easy to use.  

Thermostats, towel bars and other bath accessories, doorbells, mailboxes, house numbers, pull chains, closet shelving, garbage disposals, light bulbs, final cleaning, and all of the other little details can all start to add up on you if you don't plan for them. 

You could get a normal thermostat for $20-$30 or a lower end WiFi Connected thermostat for $60.

Add a programmable thermostat.21.

In addition, he told me that there is currently only one thermostat for the entire house, and that it's difficult and expensive to zone on a steam boiler.