Typically if you stick with the big guys, American Standard/Trane,   Carrier/Bryant,  Rheem/Ruud,  Lennox or Goodman/Daikin/Amana you'll be ok.  

"The credit check is an industry standard decision rating based on the applicant's credit score and public records.

Personally, we don't advertise/show a unit until it is vacant, clean, and ready to move into, so that prospective tenants can see what they're getting and know what our cleanliness standards are. 

The longer terms will cause you to rank more favorably in searches that fall outside of the standard search of "single family homes".

@Mark Bookhagen is right, 2 tax returns is what I've found to be the standard before you can use it as income.

I have condo rentals, I've been an HOA president and have been involved in different HOAs, and the one thing I've learned is that rentals need to be held to a higher standard by the owner/landlord. 

Congrats and Thank You for keeping keep the Landlord reputation at a high standard!

Decent pricing and lead time on all my standard equipment.

The front flower beds have some standard bushes in them, or at least they would be standard if they did not have those wire Christmas reindeer planted in the middle of them (bush and ornament are now one).

They are much more flexible and don't have to adhere to all the conventional loan standards.