The pilot light ignights but as soon as I let the knob out to light the heater the pilot goes out. I also noticed that when I depress the pilot knob I can not hear the gas coming out like I use too. I have tried 2 different full bottles of propane with the sqme results.

Sounds like it is shorting out on the pilot knob

Unit dosn't seem to bve sensing flame. Clean your flame sensor. Its connected to your pilot light assembly usually. Its a metal rod that sits inside the flame. Could also be bad and need replaced. Hope this helps.

SEt to pilot, Push knob, push pezio ignighter until pilot lights, hold for 30 seconds. if it stays lit turn to on, if it doesn't stay lit, you have a bad thermocouple

There is a thermocouple that detects that there is a pilot flame so that main gas won't come on unless there is a pilot. That thermocouple is faulty. These are available from a plumbing supply house. The thermocouple will be attached right in the flame from the pilot and connects back into the gas valve.

Dust has built up in the ODS pilot safety. Blow out the pilot or flush it with Rust Buster. Let it dry and retry.
How it works/What to clean HERE

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Is there a "Pilot" marking on the knob? Try moving the knob 1/2 way between on and off and depress the knob. If you are in the correct location, the knob should depress in about 3/8 of an inch. Once you find the location where you can depress the knob, there should be a red sparker button that you can snap to light the pilot. Depress the pilot knob and snap the button a few times. There may be a small viewing port at the pilot. It may be covered by a small metal shield held on by a thumb screw. You can remove the shield to view the flame. OK so now you can depress the pilot knob, snap the sparker, look for the flame while still holding down the pilot knob and count to 30. Slowly release the pilot knob and check to see if the pilot is still on. Once it stays lit, rotate the knob to the "ON" position.

Are you referring to the Pilot setting on the gas valve knob? if so, you probably have a bad thermocouple or it is not in the flame enough to sense flame. Inspect the pilot to make sure the thermocouple is in the flame. If so, change it.

Just to make sure you are trying to light the pilot, from the gas valve follow the small diameter pipe (1/8") to the pilot assembly. Where you should be placing your flame is above that point. Now with the gas valve knob turned to the Pilot marking, depress the know into the gas valve. Light the pilot. Check to see if it is lit and remain holding the knob in for 30 to 45 seconds. If the flame goes out as soon as you let out the knob, you will need to replace the thermocouple.

Sounds like you need a new thermo couple. found at most hardware stores

make sure the flame hits the thermo couple if so then replace it lows has them in the water heater section thermo couple gets hot makes millivolt signal then opens gas valve