B737 captain reported a fuel imbalance due to an incorrect MEL application.

Attributes
ACN	1523648
Time
Date	201803
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Dawn
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Fuel Distribution System
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 353 Flight Crew Type 12000
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural MEL Inflight Event / Encounter Fuel Issue

Narrative:

MEL 28-3 was on the release; indicating center fuel tank boost pump low pressure warning light was inoperative; left. On climb out of ZZZ we noticed a fuel imbalance developing very quickly. Fuel was burning out of the number 1 wing tank. We opened the fuel cross flow valve. This stopped the imbalance; now fuel was coming out of the center tank to run both engines. Max imbalance was 800 pounds. Once fuel was depleted from the center tank; we balanced the wing tanks closed the flow valve and continued the ZZZ1. It was very apparent to us that the fuel pump was inoperative. An improper MEL was applied.

Original NASA ASRS Text

Title: B737 Captain reported a fuel imbalance due to an incorrect MEL application.

Narrative: MEL 28-3 was on the Release; indicating Center Fuel Tank Boost Pump Low Pressure Warning light was INOP; left. On climb out of ZZZ we noticed a fuel imbalance developing very quickly. Fuel was burning out of the Number 1 wing tank. We opened the fuel cross flow valve. This stopped the imbalance; now fuel was coming out of the center tank to run both engines. Max imbalance was 800 pounds. Once fuel was depleted from the center tank; we balanced the wing tanks closed the flow valve and continued the ZZZ1. It was very apparent to us that the fuel pump was INOP. An improper MEL was applied.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.