Warning What does this mean?

Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.

GoodWe Inverter Error 16 — External Fan Fault and How to Respond

Error 16 — 'EFan Fault' — means the external cooling fan on your GoodWe inverter has failed. That fan moves air across the heat sink to keep the power electronics cool; without it the inverter will derate its output or shut down entirely to protect itself from overheating.

What should I do first?

Two quick questions — we'll point you to the right starting point.

Is this code still showing on your inverter's display?

What this code means

GoodWe's manual lists code 16 as 'EFan Fault' with the description 'External Fan Failure.' Inverters generate real heat while converting power, and the external fan is a core part of the thermal design — especially for units mounted in warm or sun-exposed spots. When the fan stops, internal temperatures climb; the inverter first reduces output (derating) and then stops to avoid cooking its components.

This is protective behavior, but every hour it runs derated or stopped is lost generation, and sustained overheating shortens component life — so a fan fault deserves prompt attention even though it is not an emergency.

Most GoodWe DT/SDT models pair the external fan with a finned heat sink, and the manual's maintenance section specifically calls out fan inspection — a sign of how central the fan is to the unit's longevity. If your inverter sits in direct afternoon sun, the fan works hardest exactly when the unit is producing most, so a failed fan in a hot climate deserves same-week attention.

What is this downtime costing you?

Rough estimate while your system isn't producing. Adjust the numbers to match your setup.

System size (kW) Peak sun hours / day Electricity rate ($/kWh)

–per day

–per week

–per 30 days

≈ – kWh of lost production per day.

Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.

Common causes

Dust, debris, leaves, or spider webs clogging the fan or its grille — the most common cause for outdoor-mounted units.
A worn-out fan motor or seized bearing after years of continuous running.
Physical damage to the fan blades or housing from impacts or severe weather.
Insects or small nesting material blocking the air path.

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 5 done.

1. Look at the fan from outside only — check whether it is spinning while the inverter is warm and producing. Never reach into the fan, poke it with tools, or open the inverter.
2. Check the outside of the grille for visible leaves, webs, or debris you can see without touching the unit. Do not dismantle anything.
3. Note any unusual heat from the casing or burning smells — a hot smell means stop and call for help.
4. Perform one documented restart (AC and DC switches off, wait 5 minutes, back on) in case it is a transient detection fault.
5. If the fan still does not run or the code returns, arrange a service visit — fan replacement is a technician job.

Is your inverter still under warranty?

Before paying for a repair, check — your installer may fix this free.

Brand Year installed

Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.

When to call an electrician

Call your installer if the fan is not spinning, the error persists after a restart, the inverter feels excessively hot, or you notice any burning smell — the last one means switch the system off via the documented procedure and call immediately. GoodWe's own manual covers fan inspection under maintenance, but fan replacement and any internal work belong to qualified service personnel. Do not run the system for weeks on a failed fan hoping it copes; chronic overheating ages the inverter prematurely.

Frequently asked questions

Can my inverter run without the external fan?

Briefly and at reduced output — it derates or shuts down to protect itself. It is not a mode to rely on; get the fan fixed.

Is it safe to clear debris from the fan myself?

Only what you can see from outside without touching the unit or reaching into the grille. Anything more — removing covers, touching the fan — is technician work.

How urgent is a fan fault?

Moderate. It is not a fire emergency, but every hot day without cooling stresses the electronics. Book the service call promptly rather than waiting for the next season.

Will a restart clear Error 16?

Only if the detection was transient. A genuinely dead or jammed fan will fail again immediately — the restart just confirms whether the fault is real.

Does heat actually damage inverters?

Yes, over time. Electronics age faster when hot, and repeated thermal stress is a common reason inverters fail years early. The fan is cheap; the inverter is not.

Need a professional?

This fault may need professional diagnosis. Contact a qualified solar electrician in your area.

Sources: meaning and troubleshooting verified against the manufacturer's documentation — GoodWe DT/SDT Series User Manual 340-00022-03 (goodwe.com) — Section 4.3 Error Code: 16 'EFan Fault — External Fan Failure'