Cosmo / Cosmo Series
Cosmo H5 error code
H5 means the outdoor inverter power module has protected itself from an abnormal electrical or load condition. TOSOT Direct calls this IPM protection and points homeowners first to airflow and power stability checks.
- Urgency
- advisory
- Verified
- Jul 31, 2026
- Fix path
- Technician
What it means
H5 means the outdoor inverter power module has protected itself from an abnormal electrical or load condition. TOSOT Direct calls this IPM protection and points homeowners first to airflow and power stability checks.
Urgency
advisory
Use only safe airflow checks. If H5 returns, stop resetting the unit and schedule service.
Likely causes
- Blocked or restricted airflow
- Dirty indoor filter or outdoor coil
- Unstable supply voltage
- Outdoor inverter module overcurrent condition
Homeowner fix
Clean the indoor filter, remove leaves or debris around the outdoor unit, and make sure supply and return air are not blocked. Do not open electrical panels or test voltage yourself.
When to call a pro
Call a licensed HVAC technician if H5 returns after airflow is clear or if lights flicker, breakers trip, or the outdoor unit will not run.
This code points to compressor and electrical or inverter work - get repair quotes from contractors in your area.
Get repair quotesRepair vs replace
Airflow-related trips are often inexpensive to correct. Inverter board or compressor-related trips can be costly, so compare repair cost against system age and warranty coverage.
See Cosmo mini-splitsYour Cosmo model
Cosmo Series model pages in the Cosmo catalog help compare this repair path with current replacement options.
- Cosmo Series 9,100 BTU R-32 115V (GWH09AWCXB-A6DN***/I / GWH09ATCXB-A6DNA1C/O)
Cosmo Series
- Cosmo Series 9,100 BTU R-32 208/230V (GWH09AWCXB-D6DN***/I / GWH09ATCXB-D6DNA1C/O)
Cosmo Series
- Cosmo Series 12,000 BTU R-32 115V (GWH12AWCXB-A6DN***/I / GWH12ATCXB-A6DNA1A/O)
Cosmo Series
- Cosmo Series 12,000 BTU R-32 208/230V (GWH12AWCXB-D6DN***/I / GWH12ATCXB-D6DNA1A/O)
Cosmo Series
For your technician
Technician note: verify airflow and coil condition, then check supply voltage, compressor current, IPM heat sinking, outdoor board diagnostics, and compressor windings before replacing electronics. Page context: Cosmo maps this display to the Cosmo Series line; source: TOSOT Direct Cosmo Series product-document manual links plus TOSOT Direct mini-split error-code guide and FAQ; display convention: match the letter H and five marker exactly before comparing neighboring codes.
Which systems show it
Cosmo Series
Sold under more than one brand
Shared with TOSOT. Cosmo and TOSOT document this code from the same manufacturer source, so H5 means the same thing on either badge and the steps above apply.
Open TOSOT H5Related troubleshooting
Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.
Related codes
Source
- Document
- TOSOT Direct Cosmo Series product-document manual links plus TOSOT Direct mini-split error-code guide and FAQ