No any configurations page or anything could be opened in my user interface. Only way was make full restart - disconnected power from my Pi5 and reconnect back. Unlucky my system is not starting anymore. It seems that data partition gone to read only and system cannot switch it in rw mode. All my backups are in same SD card, but I do not know how to get them. Other linux system also does not read that disk, complaining about bad superblock or similar… Mounting commands returns errors. How to get my data?
The only way is to send into a data recovery center and that will not be cheap, so your best option is to start fresh and not to keep backups on the storage being actively used.
I agree with Robert - not much you can do if you can’t read the SD card. A tool like Ddrescue may help (I have never used this and I do not endorse it).
If / when you do recover, I highly recommend following the guidance here: Disaster Recovery Planning.
As suggested try with a Linux pc with dd_rescue.
I did it some years ago with a digital camera SD card and was able to recover most of my photos.
In your case I’ll point to recover the most recent backup file.
Having that reinstall on a new card and restore.
Then:
- move the HA folder (or at least the backup location) to an external “traditional” drive. SSD are a lot cheaper now, a traditional drive is way better than any thumb drive.
- use a tool like raspiBackup to save your setup elsewhere
- Test test test the recovery process
- If HA functions are mandatory for your house think on it and plan for downtime situations
I’ll avoid talkin on barn doors etc etc…
Also photorec can be an option.
Somehow used to restore my supervisor directory from old sd card. Took new sd card 64 GB and installed brand new HAOS image from Raspi homepage, then found very old backup and restored it and copied all the last files from restored supervisor directory. Everything looks fine, but can’t get my w1 bus temperature sensors to work. Manuals in internet tells about adding line to /boot/config.txt or mnt/boot/config.txt in HA case and I remember I did it with old HAOS installation … but made ssh access to my operating system and cannot locate boot directory or any config.txt file, the mnt directory is empty without any folders or files. How to configure onewire bus?
That tool definitely helped me! Thank you!
What??
You didn’t learn?
Ok… see you in a few months again. 
No idea what w1 bus is but HAOS has no config.txt that is part of raspos (or what ever its called this week).
And make sure you have remotely stored backups, google drive backup is good and always works. Buy yourself an SSD and usb adapter and chuck out your SD cards.
I am going to put backups out of that sd card, but first I need get everything back to working state as these wired sensors driving my heating system in home and winter is coming 
I would suggest you use ESP-Home for external projects like that.
I know, but the Pi is right there…
But if the Pi goes bust like now you are out of options.
With ESP-Home you just need to get Home Assistant running and it’s online again.
You can even enable the internal web server on ESP-Home and connect to the ESPs wifi to change things.
Don’t put everything in one basket and especially if the basket is SD card related
If using HA OS on an raspberry Pi, yes there is a config.txt. The config.txt has more or less the same function as a BIOS or EFI on a x86/am64 system.
Easiest way: stop HA OS, put the sd-card in a PC, the config.txt is in the only Windows-readable partition on the sd-card. (The other partitions are ext4, windows can’t read them)
I have esphome connected to HA, but temperature sensors was connected before and I haven’t time right away make new connections and rewrite automations. Also I do not like wifi connection between ha and esphome - not safe.
Nothing. Windows recognize 8 disks and offers format them to use if I click on any of them 
Windows do not see anything readable here…
Then, if you don’t have a linux pc, you will need to attach a screen and keyboard to your Pi, if I remember correct it is located in /mnt/boot
(Neither of the 2 ssh add-ons gives you enough rights to that directory because you are locked in their docker container, but if you don’t have a monitor and keyboard, you could ssh to port 22222, but that is difficult to set up)
I have Linux pc. There are 3 disks opening automatic haoss-data, haoss-overlay and just 25MB drive with one file, named image. Nothing more is mounted
find / -name "config.txt"
Yesss! There was unmounted partition haoss-boot. Mounted it and here it is! Now temperature sensors work! We did it - thank you!