My Atwood water heater worked great. In fact, it sounded like the afterburner on an F-15 fighter jet. Until one day it suddenly didn't.
I went outside so see if I had any flame at all. I did but it was a lazy, yellow, sooty flame.
This happened quite suddenly, within the span of a few hours. I tried all the simplest stuff first. I took the assembly apart and checked for obstructions, tried adjusting the air intake… nothing made a difference. Given that my coach is a 1995 and the water heater is original, I thought maybe the propane regulator had simply gone bad. I bought a new $95 propane regulator but that still didn't fix the problem.
Eventually I did fix it and it once again sounds like an afterburner on a fighter jet. The fix was simple and FREE. I recorded a video to explain.