2011 hot spot circulation control scheme

[998011547]

2011 hot spot relay , 1 wavemaster 6000 single speed and 1 wavemaster 6500 2 speed pump
2 speed pump took a dump, and i had a single speed 7000 but it wont seem to do the circulator function when connected to lo speed .
terminal on control board.
specifically im wondering if anyone is familiar with this gen hot spots' circulation control scheme.
It would seem that when heat is on
the two speed pump should run on "low"
any help would be appreciated
i can get the tub to run and
energize heater , but only if jets are
running ,pumps on high...

 

[RDspaguy]

In many spas the heater is driven by an independent circ pump. The high speed jets may force enough water through to make it work without the circ pump.
But it could be a flow problem. Remove your filter(s).
Post pics of equipment area and circuit board so I can see what controls you've got in there.