I'd wager the circ pump failed, leading to the green flashing light. Have you checked the circ pump for proper flow? The circ pump runs hot no matter what, but if it's failed, it could be very, very hot.
Make sure your filters are clean, and check for circ pump flow. If you don't have flow, the ready light might flash due to the heat buildup in the circ pump, and the circ pumps proximity to the control thermistor.
If that's the case, the thermistor is fine, and only the circ pump needs replacement.
Looking or ozone bubbles isn't a good way to check for circ pump flow, the ozone system can fail for any number of reasons, yet the circ pump may still have good flow
