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.

Growatt Inverter Error 102: Meaning, Causes & Safe Fix

Error 102 means the inverter's two internal processors are getting inconsistent readings — often triggered by unstable grid voltage or frequency. The inverter shuts down as a precaution.

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

Your Growatt inverter has two processors (master and slave) that constantly cross-check each other's measurements. Error 102 appears when the data they receive does not match — a 'consistent fault'. Growatt's own documentation notes this is frequently caused by the utility grid voltage or frequency changing rapidly.

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

Unstable grid voltage or frequency (most common, per Growatt's documentation)
Loose or poor AC wiring connections
Internal control board fault

Safe steps to try

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

Write down or photograph the exact error on the display, and note the time it appeared.
Check whether lights or appliances in your home are flickering — a sign of grid instability.
Perform an orderly restart: turn off the AC breaker, then turn off the DC switch. Wait 2–3 minutes.
Turn the DC switch back on, then the AC breaker, and watch the display.
If the error returns, note how often — frequent recurrence points to a grid or hardware issue.

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 or Growatt service if Error 102 persists after 2–3 restarts, appears daily, or returns immediately after every restart — the control board may need replacement.

Frequently asked questions

Is Error 102 dangerous?

No — it is a protective shutdown. The inverter stops itself when its processors disagree, which is the safe behavior. But repeated occurrences need professional diagnosis.

Can I fix Error 102 myself?

A restart clears it if the cause was a brief grid fluctuation. If it keeps coming back, the fix (control board replacement or grid investigation) is a job for your installer.

Does Error 102 mean my inverter is broken?

Not necessarily. Growatt documents grid voltage and frequency swings as a common trigger. Only if it persists after restarts does it point to an internal hardware fault.

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 — Troubleshooting for Growatt TL&MTL (Ver1.2) 2013-7-15, Growatt New Energy (applies to Growatt 1000–5000 TL, 2500/3000MTL, 3600–5000 MTL); detail corroborated by Growatt 1-3K-US User Manual error table