The fridge is easy to get at from outside, so you can see the burner etc and clean it.
With our furnace you can't get at the burner etc. Just the exhaust pipe (which was full of dead wasps and nesting when we first got the MH and the furnace didn't work until that got cleared out. Perhaps we still have some of that trouble farther in where we can't get at it, don't know)
I can't hear the furnace click sometimes from inside, but can hear it when standing outside by the furnace. When gas finally gets there, it stays clicking and it goes boom te de boom for a little then stays lit. After that, it fires right up when cycling each time.