Things that increase or decrease your rent are things that cause the utilities to go up or down, such as size, number of shared walls, utilities, appliances, type of heat, any energy efficiency features, etc.

@Christopher Munn No reason to wait-it is heat and you need it now-right?

Vinagear scrub the walls and ceilingsOil based Kilz paintClean the flooring with vinagear Ozone machine when not working in the propertyClean out the duct workReplace anything that is fabricReplace AC filters and run constantly and then replace againScrub the fridge coils and any surfacePaint it againClean it againRepeat process as needed (it sucks and it takes someone moving in and absorbing the rest of the smell)Whatever you do don’t turn of the electricity to the unit.  

The listing says "separate electric," but there's a gas hook up and forced air heat is noted.

A few minor more tactical points -  is the duplex metered where you can even make each tenant pay for water, electric, heat? 

I have tenants who crank up the heat in the winter while their windows are open.  

They're no more dangerous than any other heating source as long as the tenant uses/maintains it properly.

My thought process for not including the major and minor repair savings, is because ideally I have already replaced all of the major long life common home expenses (roof, appliances, heating and air, etc).

Just to get the heat, water, gas and electric back on can have a lot of unknowns involved.

Block constructed houses also take less to cool/heat and the insurance savings is significant.