Moving out of primary residence, and want to rent it out?

If I move out of my current primary residnence, and rent it out, am I legally obligated to bring it to my current lenders attention? I do currently live here, and did not acquire the loan with any intent to defraud anybody, but I'm also not keen on stirring up unnecessary trouble. I actually don't believe they even DO investment loans. Could they obligate me to go through the trouble of refinancing with another company or something like that?