Solar PV

Solar monitoring app not syncing

Warning Do not attempt any electrical or gas work yourself. Always use a qualified, MCS-certified, or Gas Safe registered professional for repairs.

What you’re seeing (symptoms)

You open your solar app (e.g. SolarEdge, GivEnergy, FoxESS) and the data is hours or days old. The generation graph is “flat” or showing zero, even though you know the sun is shining. The app may say “Communication Error” or “Logger Offline.”

What’s normal vs not normal

Normal:

  • A 15-30 minute delay in data appearing in the app (most systems upload in “batches”).
  • The data not updating overnight when the inverter is in “sleep” mode.

Not normal:

  • The app showing zero generation for a full sunny day while your house is still powered.
  • The inverter’s “Comms” or “Wi-Fi” light being solid red or off.
  • The app requiring you to re-pair the Wi-Fi every week.

Likely causes (ranked)

  1. Weak Wi-Fi signal: The inverter is in the loft or garage, too far from your home router.
  2. Router change: You have recently changed your Wi-Fi password or provider and haven’t updated the inverter.
  3. Manufacturer server maintenance: The “cloud” where your data is stored is temporarily offline.
  4. IP address conflict: Your router has assigned the same address to two devices, confusing the inverter.
  5. Faulty data logger: The internal Wi-Fi “dongle” or GSM module has failed or come loose.

Quick checks you can do safely

  • Check the inverter: Look at the screen or LEDs on the inverter. Is there a Wi-Fi or “Cloud” icon? Is it flashing or red?
  • Reboot the router: Many connection issues are caused by the home router, not the solar system.
  • Power cycle the inverter: Switch the inverter off (both AC and DC switches), wait 30 seconds, and switch it back on to reset the comms module.
  • Check the signal: Take your phone to where the inverter is. Does your phone have at least two bars of Wi-Fi?
  • Check the dongle: If your inverter has a USB Wi-Fi stick (dongle) at the bottom, ensure it is pushed in fully.

When to call an installer

  • If the system remains offline after a full power cycle and router reboot.
  • If you cannot access the inverter’s “internal” Wi-Fi hotspot to re-enter your password.
  • If the data logger/dongle is physically damaged or has no lights.

Questions to ask your installer

  • “Can we install a Wi-Fi extender or a hardwired ethernet cable to the inverter?”
  • “Is there a firmware update for the communication module?”
  • “Can you verify the signal strength (RSSI) from the inverter’s location?”

Related NetZeroNow tools & guides

FAQs

Is my solar still working? Usually, yes. Monitoring is separate from generation. If the app is down, the panels are likely still producing power and saving you money, you just can’t see it. Why does it use a ‘dongle’? To make the inverter “smart.” Most inverters have a USB or RS485 port where a Wi-Fi or 4G module is plugged in. Can I use an Ethernet cable? Yes, and it is highly recommended. A wired connection is much more reliable than Wi-Fi, especially for inverters in lofts or garages. What is a ‘Portal’? It’s the website where your data is stored. You can often see more detailed information on the manufacturer’s web portal than you can in the phone app. Do I need an account? Yes. Your installer should have set up an account for you and “commissioned” the inverter to your specific serial number.\n

Written by NetZeroNow | Last updated on 2026-03-02