More findings:
1. The 2x FAV Tee is good electrically.
2. One of the two coil is open circuited, the other is perfect
3. The flow sensor is good except the disc filter is 50% blocked (unusually dirty). New filter is now in place.
4. The restrictor is OK.
The controller is good. Did you install the aquamist intank filter?
I will check the flow the the FAVs and examine the internals on Monday.