MRCOOL / DIY 5th Generation
EH 0A error code
The indoor PCB main chip does not receive feedback from the indoor EEPROM chip.
- Severity
- technician
- Verified
- Jul 18, 2026
What triggers it
The indoor PCB main chip does not receive feedback from the indoor EEPROM chip.
What to do
- Shut off power and turn it on 2 minutes later.
- If the error still displays after the restart, replace the indoor main PCB.
- If the error does not display after the restart, treat the unit as operating normally.
Reset procedure
Shut off power and turn it on 2 minutes later.
Which systems show it
- MRCOOL DIY 5th Generation single-zone 9k, 12k, 18k, 24k, and 36k D25 indoor/outdoor models listed in manual section 1.1.
Related codes
Technician scope
Indoor PCB
Source
- Document
- data/sources/mrcool-diy5-service.pdf
- Section
- 4.7 TS01-IDU: Indoor EEPROM parameter error diagnosis and solution
- Page
- 54