Our albino bristlenose Spook likes resting on the heater near the outflow pipe and his bristles get blown about like mad in the current. He looks so funny!
Id either put a cover on the heater or move the heater so he cant sit on it. I had the same problem with my Hoplos they managed to burn all their whiskers off, took a few weeks for them to grow back again .
Many people have seen burnt plecs, or cooked plecs becuase they sat on the heaters.
The heater has got a cover on it, he sits on the cover. Wherever we move it he still sits on it and doesn't seem to have come to any harm so far. The heater used be housed in a box in the corner of the tank but we needed to get a new one a few months ago and couldn't get one that fitted inside the box.