Owner said it has updated electric and copper plumbing newer forced air furnaces and c/a conditioners and some more updates. 2 of the 6 units are vacant and 3 units are being rented at $900.00/month with one unit being used to house the property manager.

Do you have an air conditioner that is relatively new and just needed a new evaporator coil or is leaking refrigerant? 

I doubt that your road should be the same as mine, and I think you should spend some time coming to grips with what's best for your market and what's best for you. well in Pacifica you would never run your air conditioner.. matter of fact you would never need one.. 

If the "air conditioner" you referred to in your post is a window unit that would fall out when you turned the house upside down, then it is 5-year personal property; otherwise, 27.5-year propertyLandscaping and ground improvements are 15 year property that would include driveway and sidewalks.For a single family rental, a cost segregation study is most likely more expensive than your tax savings could ever recover through accelerated depreciation. 

Example: tenant calls me yesterday to tell me air conditioner stopped working.

Have you made any major improvements to the home like roof, replaced furnace, air conditioner, etc? 

Other than it being smaller, painting a house between tenants is going to cost the same, a new roof will cost the same, a new air conditioner, hot water heater, furnace will be the same cost etc.For instance, it costs us about $1,000-$1,500 plus a months rent as a leasing fee. each time we change tenants, by the time we paint, do landscaping, repair damage, change locks, patch holes, paint walls that need to be painted get a make ready clean. 

We had the cheapest beer in town and a window air conditioner. 

In Las Vegas, the most expensive (typical) repair item is an air conditioner compressor, costs about $2,500.

Michael Frankel I buy $1 bottles of shampoo, conditioner and body wash at Maxway (or similar), and offer those.