# JASC 7312: Fuel Heater

- Type: JASC system/component code (FAA)
- ATA chapter: 73 Engine Fuel and Control
- Title in the code table: FUEL HEATER
- Service difficulty reports: 254
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=62
- Page: https://openairdocs.org/jasc/7312

## What it covers

The unit which heats fuel flowing to the engine to prevent freezing of entrapped water. Does not include connecting lines or the heat source.

## Service difficulty reports (254, newest 50)

- [SDR SWAA2026100150161](https://openairdocs.org/sdr/SWAA2026100150161), Sep 27, 2026: Boeing 7378H4. O-RING. LEAKING. APPARENT FUEL LEAK FROM #1 ENGINE COWLING. NR 1 APPARENT FUEL LEAK FROM NR 1 ENGINE COWLING. R & R NR 1 ENG SERVO FUEL H (N8577Z)
- [SDR YENA2026033000349](https://openairdocs.org/sdr/YENA2026033000349), Mar 30, 2026: Airbus A321271NX. PUMP. FAILED. FLT # 933 BOS-SFO (ETOPS). ENG 2 FUEL HEAT SYS DEGRADED ( HEAT SYS DEGRAD CAUTIONS ON ECAM E/WD ). INSTALLED NEW IFPC ON (N2180J)
- [SDR JIKA2024062801](https://openairdocs.org/sdr/JIKA2024062801), Jun 27, 2024: Beech C99. O-RING. LEAKING. DURING CRUISE FLIGHT WITH THE AUTO PILOT ACTIVE THE FLIGHT CREW NOTICED THE #1 FUEL FLOW GAUGE WAS NOT WORKING. AFTER PE (N992AF)
- [SDR ASAA2023101545621](https://openairdocs.org/sdr/ASAA2023101545621), Oct 15, 2023: Boeing 737990ER. FUEL HEATER. LEAKING. FUEL STREAMING OUT OF TOP CAP OF #1 ENGINE SERVO FUEL HEATER DURING MOTORING PROCEDURE. GROUNDED - YES. REEMOVED AND REP (N487AS)
- [SDR ASAA2023091345116](https://openairdocs.org/sdr/ASAA2023091345116), Sep 13, 2023: Boeing 737990ER. HEAT EXCHANGER. LEAKING. PILOT REPORTS FUEL LEAK #2 ENGINE. GROUNDED - YES. (RESOLVED ON W/O: 1969467 TASKCARD: N/R-00001 ) REPLACED MAIN OIL/FUE (N462AS)
- [SDR AALA202305115493](https://openairdocs.org/sdr/AALA202305115493), May 1, 2023: Boeing 737823. FUEL HEATER. UNSERVICEABLE. AIRCRAFT WAS GROUNDED: ON TAKEOFF THE NUMBER 1 ENGINE DID NOT DEVELOP FULL TAKEOFF THRUST AT 26 K MAX. NUMBER 1 SHOWED 9 (N957NN)
- [SDR ASAA2023010241392](https://openairdocs.org/sdr/ASAA2023010241392), Jan 2, 2023: Boeing 737890. FUEL HEATER. LEAKING. #2 ENG SERVO FUEL HEATER LEAKING. GROUNDED - YES. REMOVED #2 ENG SERVO FUEL HEATER REF B737-800 AMM 73-11-01. INSTALLED  (N506AS)
- [SDR ASAA2022112140886](https://openairdocs.org/sdr/ASAA2022112140886), Nov 21, 2022: Boeing 737990ER. FUEL HEATER. LEAKING. #2 ENGINE FUEL HEATER SERVO LEAKING FROM CAP. GROUNDED - YES. REPLACED SERVO FUEL HEATER PER B737-900 AMM 73-11-07. LK A (N462AS)
- [SDR ASAA2022111140758](https://openairdocs.org/sdr/ASAA2022111140758), Nov 11, 2022: Boeing 737990ER. FUEL HEATER. LEAKING. PERFORMED IDLE RUN LEAK CHECK ON #2 ENGINE PER B737-900 AMM 71-00-00, SHUT DOWN ENGINE AND OPENED FAN COWLS PER AMM 71-1 (N471AS)
- [SDR AALA202110152318](https://openairdocs.org/sdr/AALA202110152318), Oct 13, 2021: Boeing 737823. FUEL HEATER. UNSERVICEABLE. AIRCRAFT WAS GROUNDED: DURING CRUISE AT FL 350 NUMBER TWO ENGINE REDUCED TO IDLE. OTHER INDICATIONS NORMAL EXCEPT OIL TE (N947NN)
- [SDR ASMF2021120700319](https://openairdocs.org/sdr/ASMF2021120700319), Sep 22, 2021: Boeing 737852. HEATER. DAMAGED. FUEL LEAK ON RIGHT ENGINE HEATER-SERVO FUEL. DURING TRANSIT CHECK, IT WAS DETECTED A FUEL LEAK AT RIGHT ENGINE. MAINTENA
- [SDR ASAA2021072035464](https://openairdocs.org/sdr/ASAA2021072035464), Jul 20, 2021: Boeing 737990ER. HEATER. LEAKING. WITH ENG #1 AT IDLE, FUEL SERVO HEATER IS LEAKING FUEL PROFUSELY. GROUNDED - YES. REMOVED THE #1 ENG SERVO FUEL HEATER R (N467AS)
- [SDR JIKA2021071401](https://openairdocs.org/sdr/JIKA2021071401), Jul 14, 2021: Beech 1900C. FUEL HEATER. CRACKED. AFTER TAKE OFF FROM KRDM, THE FLIGHT CREW REPORTED RIGHT OIL PRESSURE WARNING ANNUNCIATOR FLICKERED AND RIGHT OIL PRESSU (N31703)
- [SDR 2021F00138](https://openairdocs.org/sdr/2021F00138), May 8, 2021: Boeing 7378. FUEL HEATER. LEAKING. LEFT ENGINE WITH FUEL LEAK AT FUEL PUMP DRAIN. DURING TRANSIT CHECK, IT WAS DETECTED A FUEL LEAK AT LEFT ENGINE. MAINTEN
- [SDR ASMF202106011](https://openairdocs.org/sdr/ASMF202106011), Apr 12, 2021: Boeing 737852. FUEL HEATER. LEAKING. DURING TRANSIT CHECK, IT WAS DETECTED A FUEL LEAK AT RIGHT ENGINE. MAINTENANCE PERSONNEL PERFORMED REVISION, DETECTING T (N845AM)
- [SDR ASMF202101022](https://openairdocs.org/sdr/ASMF202101022), Jan 17, 2021: Boeing 737852. FUEL HEATER. LEAKING. AIRCRAFT RETURNED TO PLATFORM DUE TO DURING TAXING, A FUEL LEAK WAS DETECTED IN THE LEFT ENGINE. MAINTENANCE PERSONNEL P (N875AM)
- [SDR ASMF202101019](https://openairdocs.org/sdr/ASMF202101019), Jan 4, 2021: Boeing 737852. FUEL HEATER. LEAKING. DURING TRANSIT CHECK, A FUEL LEAK WAS DETECTED IN THE LEFT ENGINE. MAINTENANCE PERSONNEL PERFORMED REVISION, DETECTING T (N958AM)
- [SDR ASAA2020081133012](https://openairdocs.org/sdr/ASAA2020081133012), Aug 11, 2020: Boeing 737990ER. SERVO. LEAKING. SUSPECTED FUEL LEAK FROM FUEL HEATER SERVO. GROUNDED - YES. REMOVED AND REPLACED #2 ENGINE FUEL HEATER SERVO REF B737-90 (N459AS)
- [SDR UIEA2020071311517](https://openairdocs.org/sdr/UIEA2020071311517), Jul 8, 2020: Boeing 76731K. FUEL HEATER. LEAKING. ON INITIAL WALK AROUND FOUND FUEL LEAK ON LEFT ENG, FUEL SERVO HEATER ASSY. REMOVED AND REPLACED LEFT ENGINE SERVO FUEL  (N1373A)
- [SDR ASMF202006019](https://openairdocs.org/sdr/ASMF202006019), Mar 18, 2020: Boeing 73786J. FUEL HEATER. LEAKING. DURING MAINTENANCE PROGRAM CHECK, IT WAS DETECTED A LEFT ENGINE FUEL LEAK. MAINTENANCE PERSONNEL PERFORMED REVISION, DET (N368AR)
- [SDR SWAA2020040230882](https://openairdocs.org/sdr/SWAA2020040230882), Mar 12, 2020: Boeing 7377H4. SERVO. FAULTY. LEVELING AT FL30; SE SLOWED TO .74. WHEN ENGINES SPOOLED UP THE #1 ENG STALLED FOR APPROX. 30 SECONDS EGT DID NOT EXCEED (N700GS)
- [SDR ASAA2020021213157](https://openairdocs.org/sdr/ASAA2020021213157), Feb 11, 2020: Boeing 737890. HEATER. LEAKING. WHILE ACCOMPLISHING TEST 9 AFTER #1 ENGINE R&R #1 ENGINE SERVO FUEL HEATER IS LEAKING. GROUNDED - YES. REMOVED AND REPLA (N563AS)
- [SDR SWAA2019120939411](https://openairdocs.org/sdr/SWAA2019120939411), Dec 6, 2019: Boeing 7377H4. SERVO. LEAKING. DECLARED EMERGENCY---------------------------------------------------------------#2 ENGINE HAD POSSIBLE FUEL LEAK. / R&R (N967WN)
- [SDR ASAA2019083030597](https://openairdocs.org/sdr/ASAA2019083030597), Aug 30, 2019: Boeing 737890. FUEL HEATER. LEAKING. SERVO FUEL HEATER LEAKING. GROUNDED - YES. REMOVED AND REPLACED THE #1 ENG SERVO FUEL HEATER REF AMM 73-11-07-000-801-F0 (N538AS)
- [SDR CA190808003](https://openairdocs.org/sdr/CA190808003), Jul 24, 2019: HEATER. MALFUNCTIONED. (CAN) DURING TAXI BEFORE TAKEOFF, THE PILOT ELECTED TO SHUT DOWN THE ENGINE DUE TO LACK OF THROTTLE RESPONSE, FOLLOWED B
- [SDR CA190703018](https://openairdocs.org/sdr/CA190703018), May 15, 2019: Dhav DHC8102. FUEL HEATER. MALFUNCTIONED. (CAN) DURING INSTALL OF FUEL HEATER ON #1 ENGINE IT WAS DISCOVERED THAT THERE WAS WHAT APPEARED TO BE MEDIA BLAST (GLASS
- [SDR ASAA2019040228916](https://openairdocs.org/sdr/ASAA2019040228916), Apr 2, 2019: Boeing 737890. FUEL HEATER. LEAKING. #1 ENG FUEL DRIPPING FROM COWL @ SIX O'CLOCK UNABLE TO IDENTIFY SOURCE/DRAIN. GROUNDED - YES. ACCOMPLISHED ENGINE VENTS  (N537AS)
- [SDR AALA2019021109002](https://openairdocs.org/sdr/AALA2019021109002), Feb 7, 2019: Boeing 757223. PUMP. WEAK. RIGHT ENGINE FLUCTUATED, N1+/- 2% +/-2%; F/F +/- #200 LBS; EGT+/- 50C. REPLACED THE HIGH PRESSURE FUEL PUMP IAW 73-11-03 (N692AA)
- [SDR ASAA2018120627238](https://openairdocs.org/sdr/ASAA2018120627238), Dec 6, 2018: Boeing 737890. HEATER. LEAKING. WHILE ACCOMPLISHING T/C N8473001 HUM INSTALLATION, FOUND NR 2 ENGINE HEATER, SERVO FUEL EVIDENCE OF LEAK. GROUNDED - YES (N518AS)
- [SDR ASAA2018112027083](https://openairdocs.org/sdr/ASAA2018112027083), Nov 20, 2018: Boeing 737890. HEATER. LEAKING. NR 1 ENG FUEL HEATER SERVO LEAKING AT THE CAP. GROUNDED - YES. REMOVED AND REPLACED NR 1 ENG SERVO FUEL HEATER REF AMM 7 (N583AS)
- [SDR QXEA2018102200377](https://openairdocs.org/sdr/QXEA2018102200377), Oct 20, 2018: Bombdr DHC8402. HEATER. MALFUNCTIONED. RIGHT SIDE FUEL TEMPERATURE WAS HOT. IT WAS FLUCTUATING BETWEEN NORMAL AND A MAX OBSERVED TEMPERATURE OF 86 DEG C, BUT I (N402QX)
- [SDR AALA2018090429005](https://openairdocs.org/sdr/AALA2018090429005), Aug 28, 2018: Boeing 737823. SERVO. LEAKING. CREW REPORTED FUMES IN AFT CABIN DURING FLIGHT. AT FL 220. THE AIRCRAFT WAS GROUNDED. TROUBLESHOT AND FOUND THE NR 1 ENG (N833NN)
- [SDR ASAA2018080225669](https://openairdocs.org/sdr/ASAA2018080225669), Aug 2, 2018: Boeing 737890. FUEL HEATER. LEAKING. NR 2 ENGINE FUEL SERVO HEATER WAS LEAKING AT IDLE. ACFT GROUNDED. REMOVED THE NR 2 ENG FUEL HEATER SERVO IAW AMM 73-11-0 (N529AS)
- [SDR ASAA2018071225349](https://openairdocs.org/sdr/ASAA2018071225349), Jul 11, 2018: Boeing 737890. HEATER. LEAKING. NR 1 ENGINE SERVO FUEL HEATER LEAKING. GROUNDED - YES. REMOVED AND REPLACED NR 1 ENG SERVO FUEL HEATER IAW AMM 73-11-07- (N588AS)
- [SDR ASAA201804304435](https://openairdocs.org/sdr/ASAA201804304435), Apr 27, 2018: Boeing 737890. HEATER. LEAKING. NR 2 ENGINE SERVO FUEL HEATER FAILED A LEAK CHECK 3A. ACFT GROUNDED. REMOVED THE NR 2 ENGINE SERVO FUEL HEATER IAW AMM 7 (N530AS)
- [SDR LR7A2018041101324](https://openairdocs.org/sdr/LR7A2018041101324), Apr 11, 2018: Lkheed 382G. FUEL HEATER. CONTAMINATED. DURING SCHEDULED FLIGHT ON FINAL APPROACH (VREF107) WHEN CROSSING THE THRESHOLD, NR 4 ENGINE FLAMED OUT. ESP FOLLOWED. Q (N401LC)
- [SDR ASMF201801018](https://openairdocs.org/sdr/ASMF201801018), Jan 6, 2018: Boeing 73783N. FUEL HEATER. LEAKING. AIRCRAFT RETURNED TO PLATFORM DUE TO A FUEL LEAK IN THE RIGHT ENGINE, AFTER ENGINE START. MAINTENANCE DETECTED THE FUEL  (N860AM)
- [SDR QXEA2017081800521](https://openairdocs.org/sdr/QXEA2017081800521), Aug 15, 2017: Bombdr DHC8402. ACTUATOR. MALFUNCTIONED. AT 25000 FT, DURING CRUISE, THE FIRE BELL CAME ON . NO OTHER FIRE INDICATIONS VISIBLE ALL ENGINE INDICATIONS WERE NORMAL (N427QX)
- [SDR QXEA2017081100514](https://openairdocs.org/sdr/QXEA2017081100514), Aug 11, 2017: Bombdr DHC8402. ACTUATOR. MALFUNCTIONED. AT 25000 FT, DURING CRUISE, THE FIRE BELL CAME ON . NO OTHER FIRE INDICATIONS VISIBLE. ALL ENGINE INDICATIONS WERE NORMA (N427QX)
- [SDR ASAA2017070321265](https://openairdocs.org/sdr/ASAA2017070321265), Jul 3, 2017: Boeing 737890. FUEL HEATER. LEAKING. NR 2 ENGINE FUEL SERVO HEATER LEAKING AT IDLE. ACFT GROUNDED REMOVED THE NR 2 ENGINE FUEL SERVO HEATER & INSTALLED SERVI (N559AS)
- [SDR ASAA2017032520264](https://openairdocs.org/sdr/ASAA2017032520264), Mar 25, 2017: Boeing 737890. HEATER. LEAKING. DURING IDLE LEAK CK FOUND FUEL LEAKING FROM NR 1 ENG SERVO FUEL HEATER ASSY. GROUNDED - YES. REMOVED AND REPLACED THE NR (N508AS)
- [SDR ABXA20170114002](https://openairdocs.org/sdr/ABXA20170114002), Jan 14, 2017: Boeing 767281. BOLT. MISSING. LEFT ENGINE FLAME OUT (SHUT DOWN) OCCURRED WHILE DESCENDING THROUGH APPROXIMATELY 10,000 FEET. THE QUICK REFERENCE HANDB (N775AX)
- [SDR ASAA2017010519265](https://openairdocs.org/sdr/ASAA2017010519265), Jan 5, 2017: Boeing 737890. FUEL HEATER. LEAKING. NR 2 ENGINE FUEL HEATER SERVO LEAKING FUEL. ACFT GROUNDED. REMOVED AND REPLACED SERVO FUEL HEATER IAW AMM 73-11-07-000-8 (N584AS)
- [SDR AALA20170123004](https://openairdocs.org/sdr/AALA20170123004), Dec 3, 2016: Doug DC982. PLUG. FAULTY. AIRCRAFT WAS NOT GROUNDED. DURING TAKEOFF ROLL THE RIGHT FUEL HEAT ANNUNCIATOR ILLUMINATED. TAKE OFF ABORTS AT APPROXIMA (N7547A)
- [SDR AALA20170123003](https://openairdocs.org/sdr/AALA20170123003), Dec 3, 2016: Doug DC982. RELAY. FAULTY. AIRCRAFT WAS NOT GROUNDED. DURING TAKEOFF ROLL THE RIGHT FUEL HEAT ANNUNCIATOR ILLUMINATED. TAKE OFF ABORTS AT APPROXIMA (N7547A)
- [SDR AALA20161205006](https://openairdocs.org/sdr/AALA20161205006), Dec 3, 2016: Doug DC982. SHUTOFF VALVE. FAULTY. AIRCRAFT WAS NOT GROUNDED. DURING TAKEOFF ROLL THE RIGHT FUEL HEAT ANNUNCIATOR ILLUMINATED. TAKE OFF ABORTS AT APPROXIMA (N7547A)
- [SDR ASAA2016111918748](https://openairdocs.org/sdr/ASAA2016111918748), Nov 19, 2016: Boeing 737890. HEATER. LEAKING. NR 2 ENGINE SERVO FUEL HEATER LEAKS FUEL. GROUNDED, YES. REMOVED AND REPLACED THE NR 2 ENGINE SERVO FUEL HEATER, REF AMM (N589AS)
- [SDR ASAA2016091918077](https://openairdocs.org/sdr/ASAA2016091918077), Sep 19, 2016: Boeing 737890. HEATER. LEAKING. WHILE ACCOMPLISHING TEST 3A-LEAK CHECK ON THE NR 1 ENGINE FOR HPTCC VAVE REPLACEMENT, FOUND LEAK COMING FROM SERVO FUEL  (N583AS)
- [SDR ASMF201611013](https://openairdocs.org/sdr/ASMF201611013), Sep 18, 2016: Boeing 737752. FUEL HEATER. LEAKING. AIRCRAFT RETURNED TO PLATFORM DURING TAXING, A FUEL LEAK WAS DETECTED IN THE LEFT ENGINE. MAINTENANCE PERSONNEL PERFORME (N851AM)
- [SDR ASAA2016083017866](https://openairdocs.org/sdr/ASAA2016083017866), Aug 30, 2016: Boeing 737890. FUEL HEATER. LEAKING. SERVO FUEL HEATER LEAKING NR 1 ENGINE. ACFT GROUNDED. REMOVED AND REPLACED NR 1 ENGINE SERVO FUEL HEATER, IAW AMM 73-11- (N516AS)

All 254: https://openairdocs.org/jasc/7312/reports.md

## Other codes in chapter 73

- [JASC 7300](https://openairdocs.org/jasc/7300): Engine Fuel and Control (465 reports)
- [JASC 7310](https://openairdocs.org/jasc/7310): Engine Fuel Distribution (1,981 reports)
- [JASC 7311](https://openairdocs.org/jasc/7311): Engine Fuel/Oil Cooler (226 reports)
- [JASC 7313](https://openairdocs.org/jasc/7313): Fuel Injector Nozzle (529 reports)
- [JASC 7314](https://openairdocs.org/jasc/7314): Engine Fuel Pump (1,734 reports)
- [JASC 7320](https://openairdocs.org/jasc/7320): Fuel Controlling System (4,390 reports)
- [JASC 7321](https://openairdocs.org/jasc/7321): Fuel Control/Turbine Engines (2,878 reports)
- [JASC 7322](https://openairdocs.org/jasc/7322): Fuel Control/Reciprocating Engines (1,272 reports)
- [JASC 7323](https://openairdocs.org/jasc/7323): Turbine Governor (544 reports)
- [JASC 7324](https://openairdocs.org/jasc/7324): Fuel Divider (74 reports)
- [JASC 7330](https://openairdocs.org/jasc/7330): Engine Fuel Indicating System (407 reports)
- [JASC 7331](https://openairdocs.org/jasc/7331): Fuel Flow Indicating (197 reports)
- [JASC 7332](https://openairdocs.org/jasc/7332): Fuel Pressure Indicating (158 reports)
- [JASC 7333](https://openairdocs.org/jasc/7333): Fuel Flow Sensor (80 reports)
- [JASC 7334](https://openairdocs.org/jasc/7334): Fuel Pressure Sensor (198 reports)
- [JASC 7397](https://openairdocs.org/jasc/7397): Engine Fuel System Wiring (532 reports)

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