I drained my '05 Tiger River Sumatran, replaced silver ionizer and filter, filled it w/ water and cannot get it to heat. I do have bubbles coming up from drain so don't think air in heater coils is the problem--or is it. And I can't get the summer icon to go away. I can get it to blink but not disappear. Manual is confusing--is it STMR+ to heat or STMR-?? With STMR-I get the summer sun icon on steady. With STMR+ the summer sun icon flashes. How do I get rid of the summer icon?