The old tenant had been there 6.5 years and so there was cost in getting the unit back to rental condition, one of the units also had the thermostat go out.

I looked on a few different HVAC web sites and I don't see parts listed except for  thermostats and complete electric baseboards.If hydronic, then yes, but you'd have to know how to drain the boiler, solder heating element to pipes, and refill/bleed all the air out.  

I also have WiFi thermostats so I can remotely change the temperature when no one is there to save on the electric bill.

In goes a copy of the lease, house rules, garbage, online payment, thermostat, dishwasher, garbage disposal and furnace filter instructions if applicable, and some basic homeowner care instructions about changing a light bulb or unstopping a toilet.

For example when I replace a cadet heater I typically spend more and replace it with the new digital thermostat ones.

I installed suntouch from Home Depot in my last bath Reno, it was under $400 for mat and thermostat.

@Jordan Malara Pikes Peak Regional Building Department does not allow for two units to have one thermostat.

We have found the best way to keep things running smoothly is to have a designated "Den Mother" in the house - in our case, my sister-n-law.4) You will be carrying all the utilities; as such, it is in your best interest to invest in programmable thermostats (with a lock-out limits on max and min temperature settings); low-flow fixtures and LED lighting.  

I looked at the thermostat and it was set at 78.

But in the 5-unit, I pay utilities.The thermostats (there are two boilers and two thermostats) are in two separate units.