The regulator freezes on my three bur...

Are you sure that you replaced it with the correct size regulator, Another thing might be the orifaces are restricted in the burner valves. The only way to check this would be with a manometer that reads in water coloumn. You also may have a burner problem if its a single burner. One thing you might do is take apart the burner(s) and blow them out with compressed air including the burner valves. But not the regulator this may damage the diaphgram.

This can happen when an excessive amount of propane gas is used or when if the tank you are using is not sitting upright, therefore allowing liquid propane to exit the tank through the regulator.