1 master thermostat that controls 3 units

[John Moon]

I'm looking into a Triplex but I found something weird about the house. The house is heated with gas, and they have radiators throughout the units. However, there is only 1 thermostat (control panel) for the whole building. It's in 1 of the units, and they control how hot they want it to be, and the other units either complies with the heat or can turn down or up their heat through the radiator knobs (not many renters know about this). 

If I was to take over this place, I would like to fix this issue so each tenant can control their own heat. Is this something that can be fixed? What type of contractor should I call?

Other info

- 1 heater for all 3 units. It's big enough and no complaints. 

[Ceril S.]

We ran into this on a duplex and decided to add another heater for the 2nd unit because otherwise we would have to carry the heating costs (which leads to waste on the side of the tenants - because one unit may be too warm and keep their windows open letting all your dollars out!)  The other options we looked at were 

- locking the 1 thermostat and having it controlled by us (and paid by us)

- Converting 1 unit to electric baseboard

- Dividing the utilities so that it can be billed separately (which is what we eventually went with - keeping the existing radiators in place and adding a separate heater)

Are all of the other utilities separate?  We have a couple properties that we bill back for water using (RUBS) but have so far kept electric and gas on the tenants bill.