GoodWe Over Temperature
Over Temperature (error 18) means the internal temperature of your GoodWe rose above the safe operating limit, so it throttled down or shut off to avoid damage. It is a protective response, and almost always about cooling and airflow rather than a broken part. Help it run cooler and it usually goes away.
Why a GoodWe overheats, most common first
- Poor ventilation or direct sun. It is in a hot, enclosed spot or taking direct sunlight on the casing.
- Dust or blockage. The heatsink fins or fan vents are clogged with dust or debris.
- Midday heat at full output. Peak sun plus a hot day plus maximum power pushes it over the limit.
- A failing fan (the one cause that needs a technician).
How to fix it safely
Let it cool first The casing can be hot during a thermal fault. All steps are external; don't open the unit.
- Power it down to cool for 10 to 15 minutes so the temperature drops back to a safe level.
- Clear the heatsink fins and vents. Make sure nothing is covering the unit and the cooling fins are clear of debris and dust.
- Get it out of the sun. Shade it, or consider a shade hood, or have it relocated to a cool, ventilated wall.
- Listen for the fan. On restart near full load, check the cooling fan spins. If it never does, that is likely a fan fault.
- Restart and watch the next hot day. If it stays online, you have solved it.
Quick decision flowchart
Over Temperature appears
↓ cool down, clear fins, improve airflow, shade
✅ Stays clear through midday heat → solved. Keep it ventilated and shaded.
❌ Returns with good airflow and a clean, shaded unit → fan or sensor fault.
↓
If it keeps returning despite good cooling, contact your installer or GoodWe.
Related GoodWe codes
FAQ
Over Temperature only happens around midday.
That is the classic sign of marginal cooling: peak sun, peak output and peak ambient heat all at once. Improve ventilation and shade. If it persists at midday, the location or the fan is the limit.
Is it dangerous?
The fault itself is the inverter protecting itself, which is good. The long-term risk is that running hot repeatedly shortens component life, so fix the cooling rather than ignoring it.
Helpful guides
Sources
- GoodWe inverter user manual and error-message list (Over Temperature / error 18 = internal temperature over the safe limit; clear ventilation, consider a shade hood).
- GoodWe installer documentation.
⚠️ Safety disclaimer. Solar inverters carry lethal DC and AC voltage even when "off", and the casing can be hot during a thermal fault. This guide covers external steps only. Never open the unit or work on wiring unless qualified. When in doubt, call a licensed installer or electrician.