Hi Mason, no, I`ve never had a problem, but I do always cover the heater with a guard. These days you can actually buy them with guards already attached, very cheap; I know someone bought one just a week or so ago for £10 ($15U.S).
I made my guard out of a plastic arrow (archery) tube, just drilled some 5/8 inch holes along the length. If you want to email me, I can send you a couple of photos of it in the pool...