Yes RSI, i did run just one of the 26-99 and it worked good, but after i added the 2nd 26-99 the wood consumption dropped.
Scott... totally understand what your saying, i think water is returning so quickly to boiler that my delta is so low now that it stays within my set 10 degree differental and not requiring the stove to run as much. i honestly didnt think it would make this much diffirence adding both 26-99 pumps, but it its so far.
Also when there is no demand for water there is no delta... it just sits and loops at same temp return and feed both temp.