Trane UPPER LAMP 6-TIME BLINK error code

What it means

Trane's troubleshooting table lists this pattern as outdoor thermistor trouble. The service manual says outdoor thermistors are detected as shorted or open during compressor operation.

Urgency

Likely causes

1. An outdoor thermistor circuit is open or shorted during compressor operation
2. An outdoor thermistor connector or harness needs service
3. The outdoor board sensor input needs service

Homeowner fix

Power cycle once only if you can do that safely. Keep the outdoor unit clear of leaves or debris around the cabinet, but do not open it.

When to call a pro

Call a licensed HVAC technician if the 6-time blink returns. Tell them Trane identifies it as outdoor thermistor trouble.

Repair vs replace

Outdoor sensor faults are usually repairable. Replacement is rarely justified unless an old system also has outdoor board or compressor damage.

• Trane ML Series 9,000 BTU R-410A 115V (NTXWMT09A111AA / NTXSMT09A111AA)

  ML Series R-410A

• Trane ML Series 12,000 BTU R-410A 115V (NTXWMT12A111AA / NTXSMT12A111AA)

  ML Series R-410A

For your technician

Technician note: use Trane's outdoor thermistor diagnostic procedure; inspect thermistors, connectors, harnesses, and outdoor PCB sensor inputs. Page context: Trane maps this display to the ML Series R-410A line; source: Trane MyLinkDrive NTXWMT-A111A(B) Service Manual, Section 9 Troubleshooting; display convention: match the letter U, letter P, letter P, letter E, letter R, letter L, letter A, letter M, letter P, six, letter T, letter I, letter M, letter E, letter B, letter L, letter I, letter N, and letter K marker exactly before comparing neighboring codes.

Which systems show it

ML Series R-410A

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Related codes

Source

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