Sunsynk F64 fault: Heat sink over-temperature
Safe to check yourself
Urgency: medium
What it means
The inverter got too hot and reduced power or shut down to protect itself. Better airflow and shade usually solve it.
Likely causes
- Blocked vents
- Inverter in direct sun or a hot garage
- Very hot day with heavy loads
What you can safely check
- Make sure the vents around the unit are clear and nothing is stacked against it.
- Check the room or garage temperature and improve shade or ventilation if it is very hot.
- Switch the inverter off for 10 minutes using its documented procedure, then switch it on again.
- If it keeps coming back, stop and call a qualified installer.
When to call a pro
If the safe checks don't clear it, or it keeps coming back, call a qualified installer.
Solar systems carry dangerous voltages. Only do the safe checks listed. If unsure, call a pro.
Source: Deye Hybrid Inverter User Manual SUN-3K…6K-SG04LP1-EU, section 7 “Fault information and processing” (paraphrased)
Sunsynk inverters are built on the Deye platform and use the same F-codes. Check your Sunsynk manual if anything differs.