[BUG] BSB-LAN disapear of MQTT / Home assistant

[jakebslo]

Before submitting a bug report, please make sure that you have checked the FAQ and troubleshooting section of the manual. Most problems that are reported to us can be solved by going through the solutions provided there.

Do not remove any of these questions! Bug-Reports that do not contain all required information will not be accepted. If you cannot provide any required information, explain why this is the case. Please write your bug report in English, BSB-LAN is used all across Europe, so writing in English allows other users to comment/benefit as well.

Version of the Arduino IDE
Arduino IDE 2.3.8

Version of the ESP32 or Arduino framework
ESP32 3.3.8

BSB-LAN Version
BSB-LAN, Version 5.1.6-20260425110220

Architecture
ESP32 olimex EVB

Bus system
BSB

Describe the bug
When I perform an automatic MQTT discovery from the BSB-LAN settings, everything appears correctly in Home Assistant, including my approximately 900 sensors, but after a while—it can be minutes or hours—the BSB-LAN disappears from MQTT in Home Assistant.

Log files - Bug reports without log files will be closed
If you cannot provide a log file, explain here why in order to prevent closing this bug report. Attach or copy/paste the log of the Arduino IDE's serial monitor when performing the actions that lead to the error. If possible start the log right before BSB-LAN boots (pressing the reset button on the board).

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
Olimex installed next to the heat pump with a 5V/2A 40Hz-50Hz/100V-240V power supply adapter (European style plug).

LiYCY shielded control cable, 2 x 0.75 mm², between the heat pump and the Olimex.

DHCP is enabled but set to static from the internet box

core_mosquitto_2026-05-06T09-14-39.119Z.log

[fredlcore]

You are using a mosquitto version higher than 2.0.15. This is highlighted in our manual:

Attention: Currently, the mosquitto broker seems to have an issue with handling larger numbers of messages from versions 2.0.16 onwards (see this bug report). If you encounter the problem that your BSB-LAN entities become "unavailable", especially after using the auto-discovery feature below, please downgrade to mosquitto version 2.0.15. However, be aware that this version has security issues, so make sure that your broker runs at least in a firewalled environment.

Another explanation would be that your broker does not retain messages which would mean that all auto-discovery messages are lost due, for example, to a reboot. This is a setting in mosquitto, not in BSB-LAN.

[jakebslo]

Same issues with another broker like EMQX.

The entities are well recognized and after a while nothing and bsblan disappears after a little while

Nothing special specified

[fredlcore]

That's strange, and I can't reproduce it here (in fact, most users use MQTT, so the issue should have surfaced elsewhere as well). I'll reopen the issue so that others can see it, and I hope you can figure out what the issue is, but if it is initially fine, then I assume that the problem is with the broker or the broker's configuration.

[jakebslo]

For your information, here's some info I have in my BSB configuration + the brokerFor your information, here's some info I have in my BSB configuration + the broker

My bad, Mosquitto, I saw version 7, but the documentation mentioned version 2, so it was completely my fault.

After switching to the new broker, my Z2M with all my Zigbee entities connects without any problems, and my Nuki connects directly via MQTT without any issues.

But when I connect BSB using automatic discovery in the settings interface, everything connects but then disappears a few hours later.

On the local BSBLAN side, I still have access, although it's a bit laggy. It loads fine, except sometimes I have to press the settings button several times to get everything to open.

I've tried removing logging logs, hiding entities, disabling them, leaving them enabled, but it always ends up the same.

[fredlcore]

I can't comment on the MQTT issue because as I said, I cannot reproduce the problem with mosquitto 2.0.15. As for the lagginess, you have quite a number of logging parameters there. They are pushed every minute, and each parameter takes around 2 seconds. So for the most part of every minute, BSB-LAN is busy polling and pushing your parameters. Maybe you reduce the number here and see if that changes anything. I'm pretty sure the state of your heating circuit changes so frequently that you need to poll its status every minute. See my YouTube video on how to do different polling intervals with HomeAssistant.

[remidebette]

Hi,

I have recently upgraded all my systems (2y backlog on BSB-LAN versions) which activated for the first time parameters autodiscovery, and I enabled more parameters (from a dozen to 54) on my BSB lan settings.

I have experienced the above, but also crashes of my ESP 32 and several reboots, and also instabilities when the ESP 32 finally starts (intermitently cannot ping it or access the web UI).
I will be publishing some PRs linked to my findings about it (full disclosure: I am helped by Claude Code)