When you light the pilot, then put on the burner, it will only burn for 20 - 30 seconds and the pilot light, burner and everything goes off. When you re-lite, the Pilot light will not stay on after you take your finger off the Pilot light button
Heating & Cooling - Endless Summer - 153100 Open Flame Patio Heater
Answers & Comments
Either the thermocouple connection into the gas control valve is loose or the thermocouple needs replacing. Also check the burner and pilot assembly inside the screen area for dust, dirt and insect build up. A clogged pilot can mimic a faulty thermocouple.
Hope this helps you in troubleshooting and solving the problem.