But I do have 15 year mortgages on my properties that are mortgaged plus a small HELOC, and I can have 1/3 of my property vacant and still make my minimum payments and basic repairs. 

Going through a refi right now to have the new valuation on the book so we can do a HELOC for the next property.

I have funded lots of deals with my HELOC.

Question though:  Had you taken the 2nd mortgage out on say your personal house in the form of a HELOC... and you got the HELOC before you bought the property in question.... would you call that no money down?   

In my opinion, a HELOC would be best for you ONLY, ONLY, ONLY if you're buying more equity in another asset. 

You need to structure the HELOC to fit your needs.

We are right at 30K in equity and starting the HELOC process to tap into the equity (We've been pre-approved, just awaiting fresh appraisal). 

By the time you reach your loan limit you should have some equity in the first 2 properties to use either by getting a HELOC or doing a 1031 exchange.

If you refinanced would you be able to bundle HELOC with Primary and pull some cash out?

Since it appreciated so much though, you do have the option of doing a cash-out refinance or HELOC and taking some of the equity out of that condo to purchase another investment property.