# SDR ASAA2019071430071

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 14, 2019
- Submitted: July 16, 2019
- Operation: Air carrier
- Aircraft: [N448AS](https://openairdocs.org/aircraft/N448AS), registered now
- Make and model: Boeing 737990ER
- Aircraft serial: 36356
- Aircraft time: 13,199 hours, 4,316 cycles
- System (JASC): [3040 · Windshield/Door Rain/Ice Removal](https://openairdocs.org/jasc/3040)
- Part: Control Unit
- Part number: 8300027904
- Part serial: 00194
- Condition: Intermittent
- Location: Window Heat
- Part time: 10,741 hours, 3,484 cycles
- Stage of operation: CR
- How discovered: O
- Nature of condition: N
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/ASAA2019071430071

## Discrepancy

RIGHT SIDE WINDOW HEAT OVERHEAT AT FL320 RAN QRH OVERHEAT LIGHT STAYED EXTINGUISHED. GROUNDED - YES. ACCOMPLISHED TSR. ON BITE OF WHCU FOUND #2, SENSOR #1 FAULT ON M321. RESISTANCE CHECK OF TEMP. SENSOR GOOD. REPLACED R2 WHCU M321. OPS CK GOOD, NO FAULTS REMAINING.

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