Toshiba Carrier / Toshiba Carrier 26 High Wall
Toshiba Carrier L29 error code
The Toshiba Carrier table lists L29 as other outdoor unit error. It includes communication error between the IPDU MCU and CDB MCU and abnormal temperature detected by the IGBT heat-sink temperature sensor.
- Urgency
- stop use
- Verified
- Jul 31, 2026
- Fix path
- Technician
What it means
The Toshiba Carrier table lists L29 as other outdoor unit error. It includes communication error between the IPDU MCU and CDB MCU and abnormal temperature detected by the IGBT heat-sink temperature sensor.
Urgency
Likely causes
- The outdoor IPDU MCU and CDB MCU are not communicating
- The IGBT heat-sink temperature sensor detected abnormal temperature
- Outdoor inverter cooling or outdoor control electronics need service
Homeowner fix
Turn the system off if L29 returns. Keep the outdoor unit clear outside the cabinet, but do not open it.
When to call a pro
Call a licensed HVAC technician for L29. Tell them Toshiba Carrier lists outdoor MCU communication and IGBT heat-sink temperature conditions under this code.
This code points to electrical or inverter work - get repair quotes from contractors in your area.
Get repair quotesRepair vs replace
Outdoor inverter and board repairs can be significant. Compare replacement if an older system needs multiple outdoor electronic parts.
See Toshiba Carrier mini-splitsYour Toshiba Carrier model
Toshiba Carrier 26 High Wall model pages in the Toshiba Carrier catalog help compare this repair path with current replacement options.
- Toshiba Carrier 26 High Wall 12,000 BTU R-454B 208/230V (RAV-HB121KRTP-UL / RAV-BP121AT2P-UL)
Toshiba Carrier 26 High Wall
- Toshiba Carrier 26 High Wall 18,000 BTU R-454B 208/230V (RAV-HB181KRTP-UL / RAV-BP181AT2P-UL)
Toshiba Carrier 26 High Wall
- Toshiba Carrier 26 High Wall 24,000 BTU R-454B 208/230V (RAV-HB241KRTP-UL / RAV-BP241AT2P-UL)
Toshiba Carrier 26 High Wall
- Toshiba Carrier 26 High Wall 30,000 BTU R-454B 208/230V (RAV-HB301KRTP-UL / RAV-BP301AT2P-UL)
Toshiba Carrier 26 High Wall
For your technician
Technician note: inspect IPDU MCU to CDB MCU communication, heat-sink temperature sensor, inverter cooling, outdoor connectors, and outdoor PCB. Page context: Toshiba Carrier maps this display to the Toshiba Carrier 26 High Wall line; source: Toshiba Carrier RAV High Wall 12K-36K Installation Manual, Section 14 Troubleshooting, Error codes and parts to be checked; display convention: match the letter L and twenty nine marker exactly before comparing neighboring codes.
Which systems show it
Toshiba Carrier 26 High Wall
Related troubleshooting
Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.
Related codes
Source
- Document
- Toshiba Carrier RAV High Wall 12K-36K Installation Manual, Section 14 Troubleshooting, Error codes and parts to be checked