As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE FLIGHT CREW REPORTED THAT THE DEICE PRESSURE DROPPED FROM 18 PSI WHEN THE POWER WAS REDUCED ON DESCENT, AND THAT THE DEICE BOOTS WOULD NOT INFLATE. MAINTENANCE REPLACED THE NR 2 HP BLEED SWITCH. SUBMITTER STATED THAT THESE SWITCHES ARE COMMONLY CONTAMINATED WITH WATER, WHICH CAUSES THEM TO FAIL.