Unable to access home assistant port 8123, connection refused

Installation Home Assistant OS
21

Hi, check https://green.home-assistant.io/ and notice the ‘Documentation’ & ‘FAQ’ at the top-right of your screen.

22

Hi, having the same problem " Unable to access home assistant port 8123, connection refused", Ping gives response to IP and homeassistant.local. It worked all fine for a long time, but now… Before having to re-install all…any tips here?

23

HA observer…all seems fine:
Supervisor connected
Support Supported
Health Healthy

24

I also got this problem since a couple of days ago. Tried rebooting twice. Can also connect to the observer.

25

Did a Core rebuild in the CLI and now it works again. Phew.

26

Core commands save the day. Thanks

27

Hi thank you, my HA did the same. Upon setup, I could reach HA through the http://homeassistant.local:8123 link,. This stopped working and now only accessible via the IP address. What could the reason be. Thank you

28

As said before, can you ping homeassistant.local?

29

Thank you! That fixed my system!

I was was away on a trip my HA instance (runing 2026.3.4 on a pi3) stopped working. Remotely connected to a computer on my home network, I could ping the system, but I got no response on :8123.

When I got home, I hooked up a monitor and keyboard and rebooted it. Surprisingly, it booked up to the HA CLI.

I ran core start and got an error complaining it couldn’t find /mnt/data/supervisor/cid_files/homeassistant.cid. So I ran core rebuild and that succeeded, after which I was able to start HA. And all is working again.

But why did the file disappear on an idle HA instance?

30

It happened again.

32

@jlv I suspect a bad storage device.

33

Which would be my fault because it's an SD card. I keep meaning to move HA from the pi3 to a pi4 CM I have; I'll move that up in priority.

34

I’d switched off everything overnight including HA, the new wifi hub and the new BT OpenReach fibre ONT. After the big on-switch this morning to all three simultaneously, and leaving it five minutes to settle down, homeassistant.local:8123 got “This site can’t be reached
homeassistant.local refused to connect.” ???

ping time to the ipv4 of the home asistant was sub-millisecond (healthy)

What worked has been to depower HA, which is on a raspberry pi, and power it back up again. After five minutes, http://homeassistant.local:4357 showed the blue screen of Home Assistant observer saying that it was healthy and connected, but :8123 was still ‘connection refused’.

Some minutes later http://homeassistant.local:8123 worked correctly, just like nothing had ever been wrong.

Can anyone say a good guess of what was stopping it from working this morning in October 2026 ?