I'm also having issues with Rheem gas valves(SIT Delta 650s). So bad there are none available nation wide......apparently if the Water Heater was manufactured November 2020 or later you are off the hook. SIT fessed up and said there was a issue on there end, and if the Rheem was made after November you should be good. My valves are Grey, haven't seen the Blue ones since 2019. Also starting in February 2021 they will be White Rodgers valves, not SIT anymore.
Mark,
Not following you on issue with Burner Assembly, I haven''t run into that. I find the Rheems to be easier to repair than the ICON or Honeywell.
I'm getting pretty sick of the failures though....Rheem used to be set it and forget it with no issues.....Bradford White has been pretty go for me.....but there Icon Valve last 6 years pretty much a given..Not sure if AO Smith or State would be better options but I'm considering them, I do like my Rheem supplier best though.