Pilot only stays lit when temp at lowest setting

[presslandw]

I have had my hot water tank evaluated by 2 different repair technicians and they were not able to correct the issue I am having. The pilot will occasionally go out and need to be re-lit, though it has not gone out in a few weeks. The bigger issue is that the temperature has to remain on the lowest setting in order to remain lit for an extended period. If the temperature dial is increased even by a millimeter, then the pilot will go out within the hour.

The heater is an A.O. Smith ProMax, and the control valve(?) is new and was professionally installed a few months ago
Photos here: https://imgur.com/a/2m59ONO

Any suggestions are greatly appreciated!

 

[Dj2]

Why was the gas valve replaced a few months ago?
From the limited information you provided, I still think that you have a defective gas valve. When you raise the temp, your gas valve fails to open and also interrupts gas flow to the pilot.
If you are under warranty, get AO Smith to send you a new gas valve.

 

[Sponsor]

 

[presslandw]

Thank you for your reply. I should have been more descriptive.

The old gas valve was not functioning at all, so it was assumed to be the culprit. It seems to be functioning OK at the lowest temp, and the pilot has not gone out for quite some time. Raising the temperature does not immediately cause the pilot to go out, but seems to tax the system causing an eventual shut-off.