Turn the thermostat to the lowest setting
Turn the gas control knob to the OFF position
Wait 5 minutes for any gas to clear
Remove the access panel and inner cover if present
Turn the gas control knob to PILOT
Press and hold the gas control knob down
Press the igniter button repeatedly until the pilot lights
Keep holding the knob down for 30 to 60 seconds
Release the knob and confirm the pilot stays lit
Turn the gas control knob to ON
Replace the access panel and inner cover
Set the thermostat to the desired temperature
If the pilot will not stay lit, turn the gas off and call a professional