Open the small door panel at the bottom of the RV water heater. Locate the fuel gauge dial and the metal hose valve inside the door.
Turn on the RV propane at the tank. Turn the tank valve to the right to start the flow of the gas.
Turn the RV water heater pilot dial to "start" and click your long kitchen lighter to get a flame. Hold the flame next to the metal hose inside the door panel. Watch for a blue flame to ignite at the end of the hose.
Close the door panel.
Go to the RV water heater and find the button marked "Light" on the outside edge of the water heater. This is the piezoelectric starter for the Direct Start Ignition, or the DSI.
Open the propane fuel flow on the tank by turning the valve to the right. Turn the water heater dial to "On".
Push the DSI button and feel the starter click. Listen and look for the blue flame to come out of the pilot light area.