Also, in the heat of the day when the unit has been running a while have the tenant look at the lines coming out of the outside unit and see if they have ice on them.

@Brian MorrisMight be worth it to look into dry ice or soda blasting.

This isn't common, but added to reason #1 it's icing on the cake.Vinyl install is VERY simple. 

Think of it this way:  If you have own an ice cream shop that is on a busy street and traffic is wrapped around your shop all day every day...would you then put up billboards over in the other part of town? 

I recently redid the entire roof of an addition, ice shield over the entire 15x20 roof & extra work caulking etc around the 5 year old skylight & after the winter freeze & thaw it leaked.

Wrap a run of ice/water shield over the edge, and install drip edge then shingles over that, or more preferably, get a single piece of aluminum flashing bent which will fit over the shingles along the top edge.

Icing on top would be a 30 year amortization, rather than 20 or 25.

I am Hvac EPA certified but I also do plumbing, garbage disposals,dishwasher,fridges,ice makers, shelf’s, basic turning of residential apartments.

Screen tenants throughly but reasonably.Depending on your area eliminate some ‘non value adds’ which can cost you time & money - water lines to fridge, ice makers, etc.Create a plan what you want it to look like - uniform color scheme in houses, common light fixtures, pulls on cabinets, etc.Even if it’s your first property tenants don’t need to know that - provide a brochure of business norms - when to call for non emergency issues, what is an emergency, how/when to pay, etc.After a few buy & holds and some procedure, BRRRR is a reasonable next step.Good luck!

Young people can step over the front of a bath tub, where the senior citizens might not want to step over the front.I’d say get a 48 inch long tub; the young party hosts can ice their beer bottles and cans in the tub ;)