Deye F26: DC Busbar Unbalanced
F26 means the inverter's internal DC bus voltage is unbalanced. It's often a brief, transient condition, and on split-phase systems it can be linked to an uneven load between the two output legs. A restart clears most cases; a stubborn F26 should be checked.
What usually causes F26
- A transient internal imbalance that settles on its own.
- Uneven loads in split-phase (L1/L2) systems, where one leg is loaded much more than the other.
- Occasionally an internal fault if it keeps returning.
The safe fix, step by step
- Wait a short moment. A transient F26 can clear by itself.
- Balance your loads (split-phase). If you have a split-phase system, spread heavy appliances more evenly across the two legs instead of piling them on one.
- Restart. Power-cycle the inverter (AC off, DC isolator off, wait, restart). It may take two or three tries for the bus to settle.
- If F26 keeps returning, contact your installer to check the system.
Quick decision flowchart
F26 appears
↓ balance loads & restart
✅ Clears and stays gone → it was a transient or a load-balance issue.
❌ Keeps returning → have your installer check the inverter.
Related Deye codes
FAQ
What does "DC bus" mean in plain terms?
It's an internal voltage rail inside the inverter that sits between the solar/battery input and the AC output. "Unbalanced" means the two halves of that rail drifted apart, which the inverter watches for and corrects.
I have a single-phase system. Why F26?
On single-phase units F26 is usually a transient that clears on restart. If it persists, it leans toward an internal issue for your installer to check.
Sources
- Deye Hybrid Inverter User Manual (F26 = "The DC busbar is unbalanced"; balance split-phase loads, restart).
- Deye dealer technical references.
⚠️ Safety disclaimer. Solar inverters carry lethal DC and AC voltage even when "off". This guide covers external load balancing and a safe power cycle only. Internal faults must be checked by a licensed installer or electrician.