Carrier / Comfort 22

Carrier EH03 error code

EH03 means the indoor unit is not seeing indoor fan speed the way it expects. The system may stop to protect the indoor coil and motor circuit.

All Codes

Urgency: advisory
Verified: Jul 31, 2026
Fix path: Technician

What it means

EH03 means the indoor unit is not seeing indoor fan speed the way it expects. The system may stop to protect the indoor coil and motor circuit.

Urgency

advisory

Try only the safe reset/check in the owner's manual. If the code returns, stop using the system until it is diagnosed.

Likely causes

Carrier Table 4 identifies EH03 as indoor fan speed out of control.
Carrier troubleshooting lists dirty filters and blocked air inlets/outlets as performance causes.
A control fault that does not clear after the manual's wait/reset guidance.

Homeowner fix

Turn the system off, clean the user-removable filter, and make sure curtains or furniture are not blocking the indoor air inlet/outlet. Power reset once if safe; if EH03 returns, call for service.

When to call a pro

Call a licensed HVAC technician if EH03 returns after the filter and airflow checks. Tell them Carrier lists EH03 as indoor fan speed out of control.

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

Get repair quotes

Repair vs replace

This is normally a repair diagnosis, not an automatic replacement signal. If a technician confirms a major board, compressor, fan-motor, or sealed-system repair on older out-of-warranty equipment, compare the quote with replacement.

See Carrier mini-splits

Your Carrier model

Comfort 22 model pages in the Carrier catalog help compare this repair path with current replacement options.

See Carriermini-splits ->

For your technician

Technician note: verify filter/indoor airflow first, then indoor fan wheel, motor feedback, harness, and indoor PCB drive/control. Page context: Carrier maps this display to the Comfort 22 line; source: Carrier 45MHHAQ High Wall Heat Pump Owner's Manual, Table 4 Error Codes; display convention: match the letter E, letter H, and three marker exactly before comparing neighboring codes.

Which systems show it

Comfort 22

Related troubleshooting

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

Mini split condensate pump problems Mini split leaking water Mini split indoor unit freezing up

Source

Carrier 45MHHAQ High Wall Heat Pump Owner's Manual, Table 4 Error Codes

Document: Carrier 45MHHAQ High Wall Heat Pump Owner's Manual, Table 4 Error Codes

Sourced Jul 2026

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