Solar Monitoring App Offline? How to Get It Back Online

An offline monitoring app rarely means your panels have stopped working. Usually the inverter is still generating and only the internet link that sends its data to the app has dropped, often after a new router, a changed Wi-Fi password or a power cut. You can normally tell which in a couple of minutes, and often fix it yourself from your phone.

Key points

• Check the inverter first. Its screen or lights show whether it is generating, whatever the app says.

• The usual causes are a new router or broadband provider, a changed Wi-Fi name or password, a weak signal at the inverter, or a router that has switched to 5 GHz.

• Most inverter Wi-Fi modules only connect to 2.4 GHz Wi-Fi.

• FoxESS, Sigenergy, Solis and SolarEdge systems can all be reconnected from your phone while you stand near the inverter.

• If the inverter itself shows a fault, or nothing on a sunny day, it isn’t an app problem. Book an inspection.

First, is it the app or the system?

Go to the inverter (usually in the loft, garage or utility room) and look at its screen or status lights in daylight. Don’t open any covers.

• If the screen shows power being produced, or the status light is its normal colour, the system is generating and the problem is the data link.

• If the screen shows a fault message, write it down. Our guide to FoxESS fault codes covers that brand; for others, the manual lists them.

• If the screen is blank on a sunny day, the inverter may have lost power. Check the solar breaker in your consumer unit, reset it once if it has tripped, and call an engineer if it trips again or the screen stays blank.

Your electricity meter or your supplier’s app is a useful second check. If the house is importing far more than usual on a bright day, the panels may really have stopped. Our guide to solar panels not generating goes through that.

Why monitoring drops out

A new router or broadband provider

The most common cause by far. The inverter’s Wi-Fi module remembers the old network name and password. A new router has different details, so the module can’t connect until you give it the new ones.

A changed Wi-Fi name or password

Same problem, same fix. It can also happen when a broadband provider updates the router remotely.

The router has moved to 5 GHz

Most inverter Wi-Fi modules only work on 2.4 GHz. Many routers broadcast both bands under one name and sort this out automatically, but some mesh systems and router settings don’t. If reconnecting fails, check that the 2.4 GHz band is switched on. Your broadband provider can help.

Weak signal at the inverter

Lofts and garages are often at the edge of Wi-Fi range, and a new extension, a metal door or a moved router can push them over. A Wi-Fi extender or a wired connection near the inverter usually solves it.

A power cut, or the system was switched off

After a power cut the module should reconnect by itself, but it can take a while, occasionally a few hours, before data appears in the app again.

The app or the account

App updates, an expired login or a system removed from your account can all look like an offline system. Log out and back in, and make sure the app is up to date.

How to reconnect the common systems

The steps below were correct when this guide was last reviewed. Apps change their menus from time to time, so if a step doesn’t match, look for the Wi-Fi or network settings for your device in the app. You’ll need your Wi-Fi name and password and your phone, and you’ll need to be near the inverter.

FoxESS (FoxESS Cloud app)

1. Open the app, select your inverter and find its Wi-Fi settings, then choose to reconfigure the Wi-Fi.

2. If the app asks, put the Wi-Fi dongle on the inverter into set-up mode by pressing its button for a few seconds until its light flashes quickly.

3. Join the dongle’s own Wi-Fi network when prompted, then choose your home network and enter its password.

4. Give it a few minutes, then check the inverter shows as online in the app.

Sigenergy (mySigen app)

1. Open the app, go to Settings and choose Network Configure.

2. Scan the QR code on the side of the unit, or type in the serial number printed next to it.

3. Join the network the unit broadcasts when prompted, then choose your home Wi-Fi and enter its password.

Solis (SolisCloud app or a web browser)

1. Press the button on the Wi-Fi stick for about five seconds, until its lights flash quickly. Don’t hold it for ten seconds or more, which resets the stick.

2. On your phone, join the stick’s own Wi-Fi network, named “Solis_” or “D_” followed by its serial number.

3. Either follow the network set-up in the SolisCloud app, or open a web browser, type 10.10.100.254 into the address bar and use Quick Set to choose your home network and enter its password. Solis’s own guide gives the login details for your stick.

4. The stick restarts. A solid green light means it has connected.

SolarEdge (mySolarEdge app)

1. Log in to the app. If you don’t have a login, ask your installer.

2. Open the menu and choose Inverter Communication, then connect to the inverter when the app asks.

3. Check the Wi-Fi status, choose Configure, pick your network, enter the password and select Join.

4. Go back to Inverter Communication and check the status shows S_OK, which means the inverter is talking to SolarEdge’s monitoring.

Other brands follow much the same pattern: put the Wi-Fi module into set-up mode, join its own network, then give it your home Wi-Fi details. The manual or the manufacturer’s app has the exact steps.

When it isn’t the Wi-Fi

If the app is back online but shows zero or very low generation on a sunny day, the monitoring is now telling you something real. Common causes include a tripped breaker, an inverter fault, a failed string of panels or new shading. Our guides to the signs your inverter is failing and solar generating less than it used to are the next step.

A battery that seems to have stopped working can also be a monitoring problem in disguise, because the app may be showing an old reading. If the battery figures haven’t changed for hours, check the connection before assuming a fault. Our guide to a battery not charging covers the rest.

What a working app tells you

Once it is back online, monitoring is the simplest early warning you have. A quick look once a week is enough to spot:

• generation much lower than the same time last year

• a battery that no longer charges fully, or empties too early

• fault messages that keep repeating

• the system dropping offline regularly, which can mean the module or the signal needs attention

Keep your login details somewhere safe, especially if you might sell the house. Our guide to buying a house with solar panels explains why monitoring access matters when a property changes hands.

Frequently asked questions

My app says offline. Am I losing generation?

Usually not. The inverter generates whether or not it is connected to the internet. Some systems store data and fill the gap once they reconnect; others don’t, so the gap stays in the history.

Do I need to switch the inverter off to reconnect the Wi-Fi?

No. Reconnecting is done from your phone with the system running. Don’t switch isolators off and on to try to fix monitoring.

Can the inverter use a 5 GHz network?

Most inverter Wi-Fi modules need 2.4 GHz. If your router only broadcasts on 5 GHz, switch the 2.4 GHz band on or ask your broadband provider to.

Does losing monitoring affect my Feed-in Tariff or export payments?

Not directly. Feed-in Tariff and Smart Export Guarantee payments are based on meter readings, not the app, so carry on submitting readings as normal.

Can you fix monitoring on a system you didn’t install?

Yes. If the steps here don’t work, we can reconnect it, replace a faulty Wi-Fi module or add a wired connection, whoever installed the system. Our solar servicing page explains what a visit covers.

Book a solar system inspection. If your monitoring won’t reconnect, or it shows the system isn’t generating, we’ll find out why.