How do I start a cold gas heater?
You may not be able to hear the gas for the pilot light, it doesn't take much. Get a long match or lighter that can reach the pilot light and try to ignite it while holding down the valve button. That button overrides the thermocouple that will automatically shutoff the gas when it cools down. You need to hold the button long enough to heat the thermocouple back up while the flame is burning (30-60 seconds is usually good). Once the flame stays lit without holding the button, you can close the water heater back up and adjust the tank thermostat back to your normal temperature.