I am looking for a thermostat that I can install where I can set the upper and lower limits of the temperature - perhaps by a passcode. 

I currently have a 2 unit on oil heat, 1 thermostat, shared ducts, so I have to foot the entire bill and it's killing my revenue in the winter, costing $1000 some months.I've looked into converting to gas and into installing electric baseboard heaters.

I checked the thermostat.

She had already checked the circuit breaker, changed the filters and changed the battery in the thermostat.

I would assume there would be problems if only one tenant is controlling the thermostat.

.- Use smart thermostats that only allow tenants to have heat within a specified time- Has energy been deregulated in your area?

Electricity can top $500/600 per month during peak monthsTurning the thermostat up to 80 during the summer is still $350/monthNatural gas used only to heat showers is $50-80 a monthWater is at least $100 a month winter, $300 summer (sprinklers)Internet is $50 a monthI know "bills paid" is never a good idea, as tenants won't be efficient.But, "all bills paid" is the norm in this area for roommates.

I figure out if there is software available to do the job, how much, if not, what programs to write in house to do it, what programmers we have to hire, what the program has to achieve, how long it will take and how much.One such business unit I interviewed trade coffee futures, and I had no knowledge of futures when I started the project.

I got a head start on a few things, and I bought a couple of 7 day programmable thermostats; they are Honeywell RTH2510B thermostats. 

Of course, if you have a vacation rental you’ll be getting those keyless remotely programmable locks anyway.