I have an older Tiger River Bengal. The heater relay board failed recently so I replaced it with a new 4th generation heater relay board. When I power the tub up the relay board functions properly and heats to the set temperature one time. Then the tub cools back down to ambient temperature.
Heater LED solid red
limit LED solid green
d10 LED flickering green
d9 LED blinking red.
If I power cycle the tub, it heats properly again one time to set temperature.
Does this mean my motherboard has failed? Or is there something else I should be looking at?