As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW RETURNED TO FIELD, DUE TO AN E2 ANTI-ICE VALVE FAIL MESSAGE ALONG WITH A CLOSED INDICATION ON EICAS WHILE IN ICING CONDITIONS. MX SECURED THE E2 ANTI-ICE VALVE OPEN AND PLACED THE E2 ANTI-ICE SYS ON MEL. THE MEL WAS CLEARED, ON THE 30TH WHEN THE HIGH STAGE PRESSURE WAS FOUND CRACKED AND REPLACED. AFTER REPLACING THE HIGH STAGE PRESSURE SWITCH THE E2 ANTI-ICE SYS OPERATED NORMALLY.