I'm working on the walls in my living room, but I can't get to the area behind the fairly new (and large) rinnai heater because the vents are attached to the wall too snugly to even slide the thing 6 inches away. Anyone know how to remove the vents from the wall? I can't even get in enough to try things out... There's plenty of room in the gas line to slide it out, just not the vents. Thanks.

pbh