Pilot light goes off new Rheem Nat Gas water heater once in a while

mitchxy

I have a 1 yr old Rheem Performance Platinum 50 gallon NG tank. A couple of months ago, the pilot went off. No status code. Nothing I did worked to turn it back on. Went to YouTube for all the solutions. There is no thermocouple switch. There was no space under the tank, so no dirty filter underneath. Tried again the next day, and the pilot lit with no problem. I still don't know why a new water heater would go out.
It happened again yesterday. Same thing; I couldn't get it to light. I did light it once, but when I turned the temperature up, it shut off, and I couldn't light it again. No status code at all. Then today, tried it again and it lit no problem. There are ventilation holes on the sides that aren't dirty. Not much air movement in the room, so shouldn't be a dust problem, but there is circulation with a window open at all times.
My old AO Smith with a manual pilot worked for 20 years and I only replaced it just because it was 20 years old.
Any clues as to why I'm having so much trouble with a new water heater? Why does it go out just occasionally? Honeywell/Resideo thingy with a pushbutton lighter.

Mad Dog_2

Intermmitent Pilot outages are one of the most enigmatic and frustrating calls in this business.  There are so many things it could be.  
1) Combustion air variations
2) Downdraft
3) Millivolt short
4) Loose Nut on pilot burner
5) Loose Thermocouple nut
6) Faulty Gas valve
7) Faulty Flame rod...
8) Pilot flame 🔥 length

Did this happen right away?  How often?  Mad Dog 🐕 

HVACNUT

Is this the gas valve?
Does it have the noxious vapor sniffer?

mitchxy

The heater is not plugged in, nor are there any flashing codes at all, just no light,
The first time it happened, maybe exactly a year into use. Then again 2 months later. Each time, it wouldn't light till the next day.

plumbbob333

thermal switch in combustion chamber