Nt-20 suburban heater 1966 ambassador

[Danny Bell]

Hi Folks,

The burner flame on my NT-20 Suburban heater has more yellow in the flame than last year. My original manual says to remove the 2-screw cover to access the primary air adjusting rod. Turn rod C.C.W. for less air, C.W. for more air.

The problem is ; The adjusting rod seems to turn in either direction with no resistance at all. Like it is just "free-wheeling". It feels like it has come loose in the valve (i think) where it goes in. Turning in either direction does nothing to the flame coloration.

Has anyone ran into this issue ?

Thanks for your help,
Dan