Growatt datalogger red light: flashing red is not a fault

A Growatt datalogger red light, on the small stick plugged into the side of your Growatt inverter, is in almost every case a sign that the system is working. Growatt’s own ShineWiFi-X manual gives flashing red as “successfully connected to the inverter”, the first successful step of three and not a fault. The state that means failure is solid green, which does not look like bad news.

The red light that is bad news lives on a different box. On the MIN TL-XH inverter itself, the manual gives solid green as normal and solid red as a fault. So the first question is which of the two devices the light is on.

Growatt data logger red light flashing: what the manual says

The ShineWiFi-X has a single tri-colour LED that has to signal four different things, so it does it with colour plus blink pattern. From the official ShineWiFi-X user manual (EN 202311):

Read it as a ladder rather than as a traffic light. The stick has three separate connections to make: down to the inverter, sideways to your router, and out to Growatt’s server. Red is rung one. Green is rung two. Blue is the top, and blue is the only state in which your data is arriving in the app.

Growatt’s combined guide for the ShineWiFi-X and ShineWiFi-S, which have the same lights, adds the solid states:

The two documents word flashing red slightly differently, but neither calls it a fault. Nothing in either table tells you that a panel is broken.

Growatt dongle or inverter: which box is the light on?

There are two devices with a light each, and their colours read in opposite directions.

A datalogger that has failed completely costs you nothing in kWh on the day it fails. An inverter in fault costs you everything from that moment until somebody notices. The two failures look equally alarming from the cupboard doorway, and they are nothing like each other in what they cost.

If you are not sure which box a light is on: the datalogger is the small stick plugged into the inverter’s communication port, and it has no screen; the inverter is the box on the wall with the display.

Growatt inverter red light: the one to take seriously

On the MIN TL-XH, the inverter’s LED is solid green when the inverter is running normally and solid red when it is in fault. That is the light worth acting on, and the display beside it will normally be showing a string and a number to go with it, for instance PV Isolation Low with Error: 203 on the MIN family.

Do not look up the number on its own. Growatt runs four numbering schemes at once, and the same number means different things in different product families: PV Isolation Low is 203 on the MIN TL-X and TL-XH but 125 on the 30-50K TL3-S/NS, and Warning 203 on the MIN and SPH is a different fault again, a PV1 or PV2 circuit short. The model-family-first version of that list is in the Growatt error codes guide.

Growatt’s own inverter FAQ documents error 217, error 401 and error 411. The word in front of the number is part of the code: in the MIN and SPH manuals, 401 is Warning 401, “Inverter communicates with Meter abnormal”, and not an Error at all. Read the whole string off the display, Error or Warning included, before you look anything up.

In practice, this is what to do with a red light on the inverter:

• Photograph the display, including the exact string and whether it says Error or Warning, before you restart anything. A restart clears the screen, and you will be asked what it said.
• Read the model number off the label on the side of the inverter.
• Look at the daily production graph in ShinePhone for the past few weeks, rather than at today’s number, so you can see whether this started today or has been happening every morning.

What a red inverter light left unread costs is on the record, in this case at a property the owner was not living in:

for the past 6 mths there has been no display in the Solax inverter and the red light is on. The installer only gives 2 yr warranty so I was advised to contact Solax direct

That is a different brand, but nothing in it is brand-specific: a red light on the inverter, left alone, ran for six months.

Solid green: the state worth worrying about

Solid green means failure: Growatt’s combined indicator guide calls it “failed connection”. The stick has stopped doing its job, in a colour that reassures at a glance. Flashing green is worse news than it looks, too: connected to the router, but the router has no internet.

So the LED table reads:

• Flashing blue: everything is working, and data is reaching ShineServer.
• Flashing green: the stick reached your router and the router did not reach the internet. Your data has stopped, and the light is green.
• Solid green: failed connection.
• Solid blue: AP mode, the configuration state.
• Flashing red: connected to the inverter. Not yet online, and not a fault in the array.
• Off: it has not found the inverter.

Only flashing blue means your data is arriving. Of the five states that do not, two are green.

Growatt datalogger offline, device offline, plant offline

If the app says offline (plant is Growatt’s word for your system), what is still online and what is not tells you where the break is. Work through it in this order:

1. Is the plant still producing? Look at today’s kWh in ShinePhone, or read the inverter’s display, or read the generation meter if you have one. If the numbers are still climbing during daylight, whatever is wrong is a communications problem and your roof is fine.
2. Datalogger offline, inverter fine? Then the break is between the stick and the internet. A new router, a new SSID, a changed Wi-Fi password or a router that has been moved further away are all in scope, and the LED tells you how far up the ladder the stick is getting.
3. Datalogger online, inverter offline? Then the chain works and the inverter is not answering. That is an inverter question, and the display and its own LED are where the answer is.
4. Neither? Something upstream of both: power to the inverter, or the AC breaker.

If you want the brand-neutral version of that separation, with the equivalent checks for SolarEdge and Enphase, the offline-or-not-producing triage covers it. If the numbers are arriving but look thin, that is a different question again, worked through in solar panels producing less than expected. Putting a number on that is a comparison against the weather, set out in check your solar production against the weather.

Will Growatt tell you when it goes quiet?

Not through the phone app. Growatt’s alerts are three tick-boxes in the ShineServer web portal: alerts, daily reports and monthly reports.

Two details matter more than the checkboxes themselves.

The first is the address. Those options go to the mailbox on the station record (the e-mail address typed in when the plant was created). At commissioning that is very often the installer’s address rather than yours. If that installer has since stopped trading, the account is the thing to sort out first: your solar panel company has gone bust.

The second is that you have to go and look. Whether those boxes are ticked on your plant is not something you can see from the outside: open ShineServer on the web, open the station’s settings, and read both the address and the checkboxes. The same check for SolarEdge and Enphase is in who gets your solar alerts. What Solmiro watches on a Growatt system is set out on the Growatt monitoring page.

Three weeks is not a worst case. Two weeks of it is what one summer holiday cost this owner:

Gutted to get back from holiday and find that the inverter stopped with an error on the day we left. 2 weeeks of prime August generation lost :( All it took was a turn off for 10 mins, then back on to resolve it but as we were away we lost out.

Reading lights is not a monitoring strategy

The light that sent you searching, flashing red on the datalogger, is, in the manufacturer’s own documentation, a sign of a working connection. The light that means your monitoring has failed is solid green. And on the inverter itself, the colours reverse again.

Which means that the information the LED carries is real but almost unusable in the way people use it: glanced at, from a doorway, once in a while, and read by colour alone. Owners describe exactly that failure mode:

I’m new to this - bought a house with panels recently … Recently I noticed that the readings don’t change and the red light is static.

The useful fact in that post is that the readings stopped moving. A number that should have gone up and did not is unambiguous in a way that no LED on either box will ever be.

On a Growatt system, the light on the stick tells you about the stick. The light on the inverter tells you about the inverter, and only against that model family’s own table. Neither of them tells you that yesterday produced nothing, and neither of them is looking while you are away. The checks that do answer it, with no colour to interpret, are in how do I know if my solar panels are working. Or let Solmiro answer it every day: it works out what the weather over your roof allowed, and it e-mails you when production falls well short of that or stops. Connecting is free.