BeastBaby
Crater Raker
If you opt to discourage it, you could build it an awning- just a several inch wide plank of plywood that would attach to the wall and come down at an angle over the top of the heater’s ledge.I like the dowel idea. My thought on the pool noodle was the same - just split it half way.
I am not sure about glue though because of fumes when it heats up.
And I still haven’t decided if my stance is to enable or discourage!