As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT STANDBY TEMP CONTROL VALVE FAILED OPS CHECK. REPLACED THE RT STBY TEMP CONTROL VALVE PER MM 21 31 11 400 801 STEPS F (1) THRU (7). LEAK AND OPS CHECK DUE 65613. ACCOMPLISHED INSTALLATION TEST OF RT STBY TEMP CONTROL VALVE PER MM 21 51 11 400 801. OPS AND LEAK CHECKED OK.