Air/fuel ratio was out of range....
Not a Main Regulator issue but a 'fuel' issue at the appliance
Due to high altitudes....less dense air therefore the mixture is fuel rich
Derating is done by changing of Orifices to small size (larger number)
Next time at altitude ..try running water heater with panel fully open
That will sometimes allow more air for combustion
Atwood Models have the air shutter for adjustments
Suburban does not
FYI: Suburban SW6DELC is a 6 gal Direct Spark Ignition with 12VDC Relay for 120VAC Element and uses a Cord to plug into an outlet
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31