As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#1 ENGINE ANTI-ICE VALVE DOES NOT ACTUATE WITH THRUST AT IDLE. THRUST NEEDS TO BE INCREASED TO GET VALVE TO MOVE. GROUNDED - YES. PERFORMED ENG#1 IDLE RUN PER B737-900 AMM 71-00-00/501 NO FAULT PERFORMED B737-900 FIM 30-21 TASK 802 OPS CHECK OK.