My suggestion is to get a boiler service guy (probably a smaller company)  out and get an estimate of what it will cost to repair the boiler so she has heat.. you don't need it working like new just want it to heat..Then you can make more decisions...OK My knowledge on boilers is not great but basically you have a oil or gas burner, a pump and pump motor,  piping and zone valves, and pressure gauge.... so, thermostat calls for heat then boiler fires up and tries to heat water .... then temp of water high enough to heat with.... then pump kicks on to circulate water to and from boiler...      

Tub was cracked due to not being supported. 2) No access panel required by code for the pump, the pump was in the rear of the tub buried under the tub deck. 3) No thermostatic anti-scaled mixing valve required by code for the roman tub filler 4) No dedicated circuit for the pump required by the manufacturer, the electrical for the tub was piggy backed on the vanity lights 5) no GFCI protection on the tub as required by code  6) no grounding of the tub motor as required by code 7) ABS drain glued to PVC drain pipe with ABS glue 8) the tub valve connections  uried with no access were IPS threaded stainless steel flexible water lines instead of hard sweated copper connections, (lost count on all the shark bites they used, they must buy them in bulk) 9) all the tile was tiled directly on the plywood of the tub deck, no underlayment to prevent the tile from being popped and the grout cracking from moisture getting to the plywood...the list goes on and on.. oh and the tub filler valve was located on the back side of the tub, not a code violation but certainly not user friendly for somebody to have to climb basically into the tub or over it to turn the water on, but that's minor in the scope of all the code violations and poor workmanship, that's just poor design. 

It would be tied into the thermostats in the units themselves.

I am wondering if a landlord of a 3500sq/ft, 4unit, section 8 compliant property can program the furnace thermostat to a specific temp (say, 70 degrees) and tenants wouldn't be able to run the bill up?

The only thing I had to do was fix their heat which hadn't worked in a year (bad thermostat, $20 fix). 

And, I like your sense of humor - which is sometimes needed in this business.Without actually walking across the house and getting mine, I think it also includes adjusting thermostats and opening cabinets, etc. and setting off the first round of insect spray "bombs" if there was a pet. 

They were mindful of closing the door, but 85 is nuts if I am paying the bill, so I put in a "landlord thermostat" which limits the heat to 73 degrees F (by law they have to be able to turn it up to at least 71).  

thanks, tyler. it think i listed most of the items somewhere in my other threads (i think i started announcing when i hit 14 or so), but i have no problem giving you the highlights again. hope i dont bore people though.cabinets - Kitchen Kompact, home depot (HD)bath tiles - http://www.homedepot.com/p/MS-International-Metro-...faucet - http://www.homedepot.com/p/Delta-Foundations-Singl...vanity - painted - http://www.homedepot.com/p/Glacier-Bay-24-5-in-Van...vanity faucet - http://www.homedepot.com/p/Peerless-Core-4-in-Cent...of this vanity - http://www.homedepot.com/p/Glacier-Bay-Shaila-24-1...toilet - toto drake or american standard cadetaccent tile - http://www.homedepot.com/p/MS-International-Arctic...kitchen tiles - http://www.homedepot.com/p/TrafficMASTER-Portland-...most pendants - http://www.homedepot.com/p/Hampton-Bay-1-Light-86-... sinks - http://www.homedepot.com/p/Elkay-Neptune-Drop-in-S...lights - http://www.homedepot.com/p/Commercial-Electric-2-L...bath timers - http://www.homedepot.com/p/Leviton-500-Watt-60-Min...bath mirror - http://www.homedepot.com/p/Zenith-16-in-W-x-20-in-...thermostat - http://www.homedepot.com/p/Honeywell-7-Day-Program...tub - http://www.homedepot.com/p/Bootz-Industries-Aloha-...disposal - http://www.amazon.com/dp/B00004U9JO/ref=wl_it_dp_o...knobs - http://www.amazon.com/dp/B006HZ2NNE/ref=wl_it_dp_o...sink grid drain - http://www.amazon.com/dp/B00GMR51XG/ref=wl_it_dp_o...shower diverter - http://www.amazon.com/dp/B001AI1VMW/ref=wl_it_dp_o...shower trim - http://www.amazon.com/dp/B001AHZRQO/ref=wl_it_dp_o...bath fan - http://www.amazon.com/dp/B00EAD6PNE/ref=wl_it_dp_o...now you can make your houses look like mine.ovens and appliances - whatever was JUST over the cheapest, dishwasher around $300.as for pics... they were linked to the original trulia listing, i will have to get that when i get back from vacation.

LED light bulbs and a wifi thermostat were the first things we did when moving to our place, not big ticket items, but they more than pay for themselves in time, especially if you leave your lights on for security/aesthetics.

If you don't want to go the route of billing by square footage, then there are meters/timers that can be added to the thermostat lines that can record the usage by each unit.