Open the panel to the RV water heater. This is usually located on the outside of the RV.
Check that the water heater is on and the tank is full of water. Look to see that the pilot light is on.
Locate the main burner unit. It is a large, square unit with a gas cock on the top and tubing that loops on the bottom. The loop attaches to another tube with a hole in it. This is the air shutter.
Examine the flame. It should burn with a mostly blue flame that has a yellow tip. Listen to the flame; it should not burn with a roaring sound. Loosen the shutter-locking screw or nut.
Open the air shutter valve by sliding it so that it is one-quarter of the way open. To correct a flame that burns too yellow, open the air shutter valve until just the flame tip burns yellow. If the flame is roaring, close the air shutter valve until you see a mostly blue flame.
Tighten the shutter-locking screw to secure the adjustments you made. Close the access panel and check to see that the unit is working properly.
