I considered doing a trade with Doug on these parts. The APO lists, I think, for about $1200 at Powerclean. I had to exchange one in the first year of my '03 Genesis, and PC said it would be around $1200 if it wasn't covered under warrantee. It was. The valve is priceless, because there are no parts available to rebuild it. It looks in the same condition that mine is.
The trade was going to be the parts in trade for my unused Rotovac.....the updated model.
I might just go with a new exchanger from Johns Heat Exchange, and a simplified APO from Greenie.