United B738 near Vancouver on Aug 3rd 2014, lavatory smoke indication

A United Boeing 737-800, registration N24224 performing flight UA-1126 from Denver,CO to Anchorage,AK (USA) with 126 people on board, was enroute at FL360 about 120nm northwest of Vancouver,BC (Canada) when the crew received a right aft lavatory smoke indication and decided to divert to Vancouver, where the aircraft landed safely on Vancouver's runway 26R about 30 minutes later. Once on the ground the crew advised there was no visible smoke, flames or haze on board.

The Canadian TSB reported the crew pulled the pin on the fire extinguisher but did not discharge the extinguisher. Maintenance examined the lavatory after landing and found no trace of fire, heat or smoke. The smoke detector was deactivated by pulling its cannon plug and the circuit breaker for hot water pulled according to minimum equipment list, the fire extinguisher was replaced, then the aircraft was released to continue the flight. The smoke detector was replaced the following day.

The occurrence aircraft reached Anchorage with a delay of 4 hours.