Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft; Human Factors
After becoming airborne climbing thru 19000 feet the flight attendants chimed the cockpit and excitedly told us the forward service door handle was in view thru the forward service door inspection window. I went to look and confirmed that the handle was visible in the service door inspection window. We were at 21000 feet and about 5 to 6 psi and had no amber alert to say the door was unsafe. In the interest of safety we elected to return to [departure airport] as we were only 10 minutes out. We landed overweight and not knowing how the door would react to depressurization on landing declared an emergency. We landed uneventfully and taxied to the gate where maintenance confirmed that the door handle was in the open position.
B737-800 pilot reported they were advised during climb by a Flight Attendant that the forward service door handle was in view through the window even though there was no door warning light.