I bought one of those 8 foot patio heaters that use a 20 gallon propane tank to replace my old one.
It will run fine for a couple of hours on a full tank and then behave like it is running out of gas. Until eventually not being able to heat at all. If I leave it off for an hour and start it back up then it runs better and can heat. If I leave it until the next night then it runs 100% until degrading slowly again.
This sounds like it is directly related to the components heating up.
My old one that I used for many years never exhibited this problem so I think I can rule out my tanks and environment.
My guess is that some metal parts in the new heater are not made of the same metal parts as in the old heater. That the metal is inferior for the task and is expanding more under heat and restricting gas flow. But that is just my wild uninformed guess.
It was suggested that I return it but how am I going to prove it's not behaving properly and if its a problem with the design getting a replacement won't help.
I am thinking of changing the regulator with the one from my old unit next.