Suburban does not have an air shutter to 'adjust' so fuel/air ratio are fixed
UNLESS LP System Pressure is HIGH (should be 11"WC with at least 50% of appliances in service)
OR
Water heater orifice has been damaged .....allowing too much gas flow
System pressure..needs to be tested/measured using a manometer and adjusted accordingly
Orifice....replace with new orifice
Circuit Board has NO Affect on amount of fuel flow....just opens/closes gas valve---energizes spark electrode
There are no 'adjustments' on water heater other then aligning burner tube, positioning spark electrode.
Simple gas flows thru a metered hole (orifice) and mixing with air (pulled in via venturi affect) and ignited by high voltage spark
IF RV Dealer 'tech' can't figure it out then they are just parts changers not TECHS
