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Device offline after router restart

The router has handed out new IP addresses: what Franzl heals on its own, and the 5 minutes that fix this for good.

What happened

Your router hands out IP addresses on a lease (DHCP). After a router swap, a firmware update, or an extended power outage, devices often get new addresses, and anything still pointing at a device's old address hits a dead end.

What Franzl heals on its own

For devices Franzl connects to directly (go-e, KEBA, Kostal, SMA, Sonnen, Fronius, and others), it scans the network on its own after a few failed attempts, recognizes the device by its serial number, and stores the new address. Usually the device is back up and running within a few minutes without you doing anything. If not: you can also enter the IP address manually in the device detail screen.

Where you need to step in: Home Assistant integrations

For devices connected via a Home Assistant integration (e.g. Fronius via the HA integration), Franzl can't redirect this itself: the address lives in the Home Assistant configuration. Franzl does detect the blind spot, notifies you, and tells you where it found the device again on the network. Then:

1. Home Assistant → Settings → Devices & Services → the affected integration
2. Reconfigure the integration (⋮ menu) and enter the new IP address, or delete and re-add the integration (history is preserved if the entities keep the same names).

Especially important for the grid meter: If it stops responding, Franzl would rather pause solar charging honestly than keep "solar charging" blindly from battery and grid. You'll get a push notification telling you where the device was found again.

When Home Assistant itself has moved

If it wasn't an energy device but your Home Assistant that got a new address, you'll notice because the app no longer connects on your home network (it keeps working while you're out — remote access doesn't depend on the IP).

In that case Franzl searches again by itself: once per app session, as soon as it notices it isn't on the home network. So usually it's enough to close the app and open it again. If that doesn't help, start the search yourself: More → Members → Gateway connection → Search on home network.

A deliberate limit: the automatic re-search only runs on the network where Franzl was last at home. If you've swapped your router and it now hands out a completely different address range (e.g. 192.168.0.x instead of 192.168.1.x), the background search won't find anything any more — then press the search button once. That's on purpose: on someone else's Wi-Fi, say at the office, the app shouldn't go probing the network on its own.

The permanent fix: 5 minutes in your router

Assign fixed IP addresses to your energy devices (DHCP reservation: the router remembers "this device always gets this address"). You'll usually find this in your router's interface under "Network" or "DHCP"; on a FRITZ!Box, look for the option to always assign the same IPv4 address to a network device ("Diesem Netzwerkgerät immer die gleiche IPv4-Adresse zuweisen"). Set this once for your inverter, wallbox, meter, and Home Assistant, and this won't happen to you again.

It's the only five-minute job in this whole help section that makes a problem disappear for good. If you're in your router's settings anyway, take care of it right away.