Been chasing this issue for a couple of years.
13 trailer has the original propane
Checked everything: lines are clear. Tank full(weighed it), new regulator, etc.
Works perfect in normal weather(45-70degrees), no problem.
BUT in colder weather, 20-40 degrees it struggles to keep the flame.
Put a pot over the top of the burner and it goes out.
Got the trailer home, warmer weather, and it works just fine.
Manometer shows good pressure at the jets( at home).
Have tried different tanks with propane
from different suppliers- same result.
I think it should work well, at least down to 0 degrees F, right?
Love to hear different ideas as to the problem.