Umm, I didn't miss jack. I read the entire thread.
Yes, the air intake is not properly sized, regardless of lint clogs. That is why peeps open it up. Why they take out the sight glass. Yada. I'm saying even opened up, it still does not draft properly.
You are confusing the two issues. The thermocouples don't fail. The pilot flame is too small for the thermocouple to create the proper voltage. As they get older, they become less sensitive. It only appears to fail. If you increase the pilot jet size, and thus, the pilot flame, the thermocouple will work again.
Listen, it gets hot in there, but not that hot. A thermocouple can take the heat. It's made to. That is how I knew the thermocouple burning up issue was a red red herring. Remember, Whirlpool does NOT know the pilot jet is too small. They think the thermocouples are going bad. They should have tested them.
Resettable whatever. You gotta remember, they are trying to keep the pilot light on without the knowledge that the pilot jet is too small. Their so called fix...is why I started to look elsewhere. That fix is just plain wrong. It is wrong to approach a problem like they have done--without trying to determine why the pilot is going out. The fix itself told me that Whirlpool don't know what the problem is. They addressed the symptoms, not the problem.
I don't know where the idea came from that it was so hot in the burner area that the thermocouples were burning up. That just does not happen. It's hot in there. It is the hottest running water heater I've ever seen. But it ain't that hot. Thermocouples are not burning up. Who told you that? Whirlpool? Don't believe everything you hear. Thermocouples are not burning up!
Even if you open the entire bottom up, like an old style water heater, you will still have issues with the pilot light going out. Replacing the thermocouple with a new one WILL work in all probability. A new one is more sensitive to the flame. But that only appears to fix the issue. The real issue is the pilot flame it too small.
In case you didn't figure it out, I'll explain it to you. ALL the issues involving this water heater are due to the pilot flame being too small. The pilot jet is incorrect. That it is getting so hot inside the burner area that thermocouples are burning up is...insane. That is not happening. It is something someone, who didn't really have a firm understanding, made up to explain the symptoms they were faced with. It made sense then, but it makes no sense now.
The pilot won't stay lit. Why? The pilot jet orifice is too small. That mimics a bad thermocouple. It thinks there is no flame. But there is. It is just too small.
Everything else is bull. No, they have no addressed it. They don't even know yet.
Umm, listen. The theromcouples are not burning up.
The reason it is not drafting right is the main problem with all the units that you missed.
The air intake which is on the bottom.
It is undersized and clogs with lint, further reducing the air flow. This raises the heat / temp in the sealed burner area which is what you feel.
They now have a resettable heat sensor on the new units and send replacement burners assembly's with the resettable heat sensor on them because of thermocouple failure and the replacement cost associated with constant replacement. The old style burners might have one go bad in a lifetime.
They have not addressed the main problem.