21
Mitsubishi Heavy
Mitsubishi Heavy air conditioner error 21
Meaning
Abnormal result of PWM algorithm
Models
SRC25QA-S, SRC35QA-S, SRK25QA-S, SRK35QA-S
How the unit shows it
- RUN lamp (tens place): Flash 2 times
- TIMER lamp (ones place): Flash 1 time
Causes and how to check
- 2 possible causes
- the cited manual page, and follow-up questions
No account needed to look up codes.