While pressing the valve control knob in, press the igniter button repeatedly until the pilot ignites. This could take anywhere from one to 10 minutes to bleed air out of the lines as the gas starts to flow. Once the pilot is lit, continue to press the valve knob inward for 30 seconds before releasing it.Click to see full answer. Herein, how do you get air out of a gas grill line? Problem: Low Flame, Low Temperature Open the grill lid. Turn off the gas at the propane tank. Disconnect the gas line from the tank. Turn all control valves to high (including the side burner if you have one). Wait for one minute. Turn all control valves to off. Reconnect the gas line to the tank. Also Know, how long does it take to purge gas line? Three full minutes should purge your line. You could also apply a continuous flame to the thermocouple allowing you to bled the air through the gas valve but this results in burnt eyebrows and mustaches sometimes. Secondly, do you need to bleed propane lines? It’s important to bleed out the gas lines, or ‘purge’ them, to ensure that all air pockets are removed. If you do not bleed your gas lines and there are air pockets in the lines your appliances may not start.How do you know if your propane regulator is bad? Top 3 Signs You Need a Propane Regulator If there are yellow or orange flames, there is likely a problem with the regulator. Other signs of incomplete combustion include soot deposits on the burner and popping sounds when the tank turns on and off.