We have a Phoenix professional patio heater that the pilot light will not light.

Try the first link.

https://www.google.com/search?q=propane+patio+heater+burner+assembly

They are still selling them!

https://www.google.com/search?q=DCS+Phoenix+Patio+Heater

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Propane Patio Heater Troubleshooting - YouTube

? 6:54
www.youtube.com/watch?v=BqYIWuDUZOUDec 12, 2008 - Uploaded by PatioShoppers Great tips about troubleshooting your outdoor patio heater. ...Pilot Light Won't Stay Lit - How to Replace a Broken Thermo Couple on Furnace ...

Hi, If the pilot light goes out when you turn the gas knob to full power on lighting them the most likely cause will be a worn thermocouple, these usually last between 2 years up to 6 years. Found this site very helpful, patio heater problem solving. They have a few solutions to checking patio heaters.

The regulator covered with frost is the problem. It freezes the gas and the gas line up. But, usually this only occurs when it has been exposed to subfreezing (in the teens) temperature for a long period of time. The quick fix, is to soak a bath towel in hot water, ring it out and quickly wrap it around the regulator. Once it thaws, the gas will start flowing again and you can light the burner. Generally, once it's flowing and being used, it won't freeze up again, right a way. Most propane companies add ethanol to the propane in the winter, to help keep it from freezing in the lines and the regulator.

Hope this helped answer you question and provided, at least a quick fix solution.

Thermocouple is faulty

A thermo couple is universal can get at lowes/Home depto

turn the gas on real slow. The air in the line is blowing out the pilot

i would try cleaning or replacing the thermocoulpe if you did replace it make sure the flame is touching the thermocouple

Sometimes you have to completely disassemble the pilot assembly to clear the blockage, the orifice for the pilot jet is very small and you can not get directly to it unless you take it apart. If this does not help, you may need a new valve.

crappy pilot flame (not properly heating the thermocouple), bad thermocouple, thermocouple loose where it screws into the pilot safety valve, bad safety valve magnet.

One or more of those is the problem.

Oh...there is also a saftey switch...in case it tips over. It will also cause the pilot to not stay lit (if the switch or wires that go to i are faulty)