Did a drain and fill today and now blinking red and green on 2007 HS Vanguard. Circ pump is running well, all jets and light work. I've re-tripped the breaker about 10 times and still blinking. The green LED is on on the main board so Hi limit is good. When I turn on the 30A for the heater a green LED illuminates on the heater board. What's the first step in troubleshooting this? Thanks!