Turn your water heater and gas supply off, and then wait about five minutes for the gas to clear.
Smell around your Suburban water heater next to the floor before you attempt to light it, since gas settles on the floor. Leave your home immediately if you smell gas and use your neighbor's phone to contact your gas supplier. Call the fire department if you cannot contact your gas supplier. Do not touch any electrical switch or light any appliance in your home. (See Reference 1 pg 7)
Turn on your gas supply and the electrical power to your water heater if you do not smell gas.
Turn the switch on your water heater to the "On" position to light the burner. The ignition device should light the burner automatically. Your water heater will try two more times before lock-out to ignite automatically if the burner does not light the first time. Lock-out means your heater stops trying to automatically ignite. (See Reference 1 pg 7)
Turn the water heater switch to the "Off" position, and then turn the switch to the "On" position after five seconds if lock-out happens before the main burner lights. This procedure restarts the ignition cycle. You may need to go through several ignition cycles to purge all of the air from the gas lines the first time you use your water heater. (See Reference 1 pg 7)
Check to ensure you have the water heater switch turned on, and your heater's gas supply turned on if the burner still will not come on.