Heloc for a Down payment?

[Robert J Koch III]

Hello all! 

I am looking to purchase my first rental property. I am currently in the looking a deal stage and have found a few perspective properties that I think will work. My question is this. I am looking to use my HELOC on my house as a down payment. Is this a smart idea? I have run the numbers on the calculators and the numbers all work out. I just can help but thinking of all that can go wrong so to speak. Thanks for any input! If anyone has any suggestions I would greatly appreciate it!