SolarEdge Over-Temperature Fault: Why Your Inverter Overheats
If your SolarEdge inverter is showing an over-temperature fault (error code 145 or 18x75), it means the internal temperature has exceeded the safe operating limit. The inverter shuts down to protect its components — but while it's off, you're producing zero electricity.
Why Inverters Overheat
Solar inverters convert DC electricity from your panels into AC electricity for your home. This conversion generates heat. Your inverter is designed to handle this heat with built-in heatsinks and fans — but sometimes environmental factors overwhelm the cooling system.
Common Causes
Direct sunlight on the inverter. If your inverter is mounted on a south-facing wall in direct sun, surface temperatures can exceed 140°F on hot days. The inverter's internal temperature adds to that.
Blocked ventilation. Inverters need airflow around them. If they're installed in a closet, behind landscaping, or with inadequate clearance, heat builds up.
Dusty heatsink fins. Over time, dust, spider webs, and debris accumulate on the heatsink fins, reducing cooling efficiency.
Extreme ambient temperatures. On the hottest days of summer, even a well-installed inverter may temporarily overheat.
SolarDoctor tracks your daily production and alerts you when heat is costing you energy.
Get your free health score →How to Fix It
- Clean the heatsink. Use a soft brush to remove dust and debris from the ventilation fins.
- Check clearances. Ensure at least 6-12 inches of clear space on all sides of the inverter for airflow.
- Add shading. If the inverter is in direct sun, consider adding a small shade structure (not directly on the inverter — maintain airflow).
- Check the fan. Some SolarEdge models have cooling fans. If yours has one, make sure it's spinning when the inverter is warm.
If over-temperature faults happen frequently despite good ventilation, it could indicate an internal hardware issue. SolarDoctor's health score helps you track the frequency and production impact of these events, giving you clear data to present to a service technician.
Frequently Asked Questions
What does a SolarEdge temperature fault mean?
A temperature fault means your SolarEdge inverter has overheated and shut down to protect its components. Inverters generate heat during operation and have built-in temperature limits to prevent damage.
How do I fix a SolarEdge overheating inverter?
Ensure the inverter has adequate ventilation — at least 12 inches of clearance on all sides. Check that vents aren't blocked by debris, cobwebs, or nearby objects. If the inverter is in direct sunlight, consider adding shade. It should restart automatically once it cools down.
At what temperature does a SolarEdge inverter shut down?
SolarEdge inverters typically begin power derating around 45°C (113°F) internal temperature and will shut down completely if internal temperatures exceed approximately 65°C (149°F). Ambient temperatures above 100°F can trigger issues.
Wondering if your solar system is working properly?
Get a free health score in 2 minutes. No credit card, no commitment.
Check Your System Now →