When grilling with a gas grill, the flame should be blue. A healthy grill flame may have a little yellow on the tips of the blue flame, but if you’re seeing a solid yellow flame, something isn't quite right. Check a few things:
The most common cause of yellow flames is low gas pressure from the regulator, which is an easy fix that you can do at home.
1. Open the grill lid.
2. Turn off all knobs on the control panel in front.
3. Turn off the tank knob. * Disconnect the regulator from the propane tank.
4. Wait 30 seconds. * Reconnect the regulator to the propane tank.
5. Slowly open the propane tank knob all the way open.
6. Turn on the appropriate control knob and light the grill per the instructions on the control panel.
If these steps helped, you can prevent the regulator from getting stuck again. You’ll want to make sure that you turn off the control knobs before turning off the valve on the propane tank. But, if this doesn't help and the flames are large and still yellow, you may need to replace the regulator.
This is another common cause for yellow flames, you may have a propane leak. Try testing for a leak.