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Toshiba Carrier / Toshiba Carrier 26 High Wall

Toshiba Carrier H03 error code

The Toshiba Carrier table lists H03 as outdoor current detect circuit error. It points to the current-detect circuit and outdoor PCB and describes abnormal current in AC-CT or phase loss.

Urgency
stop use
Verified
Jul 31, 2026
Fix path
Technician

What it means

The Toshiba Carrier table lists H03 as outdoor current detect circuit error. It points to the current-detect circuit and outdoor PCB and describes abnormal current in AC-CT or phase loss.

Urgency

Likely causes

  1. The AC current transformer is seeing abnormal current
  2. Phase loss or an outdoor power condition is present
  3. The outdoor current-detect circuit or outdoor PCB needs service

Homeowner fix

Turn the system off. Do not reset repeatedly or open the outdoor electrical compartment.

When to call a pro

Call a licensed HVAC technician for H03. Tell them Toshiba Carrier identifies H03 as current-detect circuit error or phase-loss related abnormal current.

This code points to electrical or inverter work - get repair quotes from contractors in your area.

Get repair quotes

Repair vs replace

Electrical sensing faults may be repairable, but outdoor board replacement can be costly. Compare replacement for older out-of-warranty systems with multiple outdoor electrical faults.

See Toshiba Carrier mini-splits

Your Toshiba Carrier model

Toshiba Carrier 26 High Wall model pages in the Toshiba Carrier catalog help compare this repair path with current replacement options.

For your technician

Technician note: check AC-CT current detection, phase loss, power supply, outdoor PCB, and current-detect circuit. 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 H and three 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

Toshiba Carrier RAV High Wall 12K-36K Installation Manual, Section 14 Troubleshooting, Error codes and parts to be checked
Document
Toshiba Carrier RAV High Wall 12K-36K Installation Manual, Section 14 Troubleshooting, Error codes and parts to be checked
Sourced Jul 2026

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