I have a 6 burner viking stove that is 10+ years old. Last night I noticed that all of the burners appear to be too high and are much more yellow than I would like. Prior to this, the burners were all calibrated correctly with stable blue flames.

Each burner has its own air intake mixing port, so I doubt they would all become mis-calibrated at once.

The flames also seem too high and lacking sufficient oxygen. Even turning down the value, the yellow flames don't go away until the flame is nearly out.

I have never seen this behavior before. But my guess is that the pressure regulator is broken or stuck open.

Is a broken regulator the proper diagnosis of this?

Are regulators repairable, maybe there is just debris in there?

Or should I just replace the whole regulator?