Frank -
Did you make/buy a standpipe that is the original Durso (upsidedown L) or the Stockman version which has the pipe inside the larger pipe, for external overflows?
I built the Stockman type for my Amiracle external overflow and had trouble with it continuing to "flush" so I made the hole in the top large enough to snuggly run some air hose through it. I use a piece about 9" long and run it down the standpipe, through the bulkhead and a little way into the drain hose. By moving this up and down you will find a "sweet spot" where the water level in your
external overflow box does not rise and fall very much, hence, no more flushes. When adjusting the air tube you need to let the water flow settle, it may take a minute or so for the rise and fall to level out - be patient. I discovered this through trial and error.
I did not have an air valve so I did not try that. It may do the same thing by limiting the amount of air that is allowed into the top chamber of the stand pipe but I do not know.
Good luck!
Steve
