B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 195
Troubleshooting
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Flight Crew Diverted; General Declared Emergency; General Maintenance Action
Aircraft
FL410 from ZZZ; we noticed a fuel imbalance; the Number Two Engine was 700 LBS lighter. We discovered the crossfeed valve Circuit Breaker (C/B) was popped and we were unable to verify its position. We ran the Crossfeed Selector Inoperative Checklist and had our Lead Flight Attendant visually check to ensure no fuel spray from the right side of aircraft. With no fuel leak indicated on Totalizers or visual; we chose to continue to our destination. But the imbalance was increasing; what seemed rapidly; with now 1;000 LBS difference between Engine One and Two.  We elected to divert to ZZZ2 as the imbalance increased. Although we did not suspect a fuel leak at this time; as we configured for landing; a deadheading Flight Attendant sitting near the overwing; reported to the Lead Flight Attendant that she thought she saw some misty spray when the flaps were lowered. As a precaution; we declared an emergency so Rescue could ensure there was not an associated leak. Rescue reported no leak and we continued to the gate. Maximum imbalance was 1;300 LBS. Contract Maintenance fixed all issues and released the aircraft.
Reporter stated he believes Contract Maintenance had replaced the fuel crossfeed valve to correct the problem.
During cruise; a B737-700 flight crew notices a fuel imbalance with #2 Engine fuel tank 700 LBS lighter. They discovered the fuel Crossfeed Valve Circuit Breaker (C/B) popped; but were unable to verify the valve's position. Imbalance increased to 1;300 LBS; crew declared an emergency and diverted.