Should I hold or sell my property with hot market?

[Mike Sheridan]

So I kind of fell into my first rental because my wife and I wanted to move and we were upside down on the house we bought in 07. I have had it rented out for 3 years now at exactly what my payment is on it so no income really but no loss with an easy going renter.  Its at a point now where I could  probably sell and walk out with $20k after selling expenses. its in a growing suburban area so I would like to keep it for a long term investment and hopefully sell 15 or 20 years from now where I could hopefully have much more equity and walk out from closing with much more cash. I also have thought about keeping it and pulling a heloc now on it to put a down payment on another rental. Any input or advice would be great. Thank you