As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA FLIGHT NR 2341: ON CLIMB-OUT OF SPOKANE, THE LAV ALARM WENT OFF FOR APPROXIMATELY 1 TO 2 MINUTES AND THEN WENT OUT ON IT'S OWN. THERE WAS NO VISUAL INDICATION OF SMOKE IN THE CABIN OR LAV. MAINTENANCE REMOVED AND REPLACED LAVATORY ALARM/SMOKE DETECTOR IAW Q400 AMM 26-12-11. PERFORMED OPS TEST IAW 26-12-11-710-801. OPS CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.