ESPHome and mqtt username + password configuration problem on HA

ESPHome
,
1

This is about configuring mqtt / Mosquitto on Home Assistant. For some reason, Mosquitto logs has these lines repeating every 5 s (with different port):

2026-06-19 10:33:41: New connection from [MYIP]:51593 on port 1883.
2026-06-19 10:33:41: Client esphome-dashboard-ccc8f773b932 [MYIP]:51593 disconnected: not authorised.

Also ESPHome Builder App logs show one of these (not repeating) which looks very related:

2026-06-18 11:47:36.732 WARNING (MainThread) [esphome_device_builder.controllers._device_mqtt_monitor] MQTT broker [MYIP]:1883 unreachable ([Errno 111] Connection refused) — reconnecting in 5s

(Where [MYIP] is my local IP address)

The things I have done before noticing these:

  • install ESPHome Builder app
  • install Mosquitto App
  • install mqtt integration
  • create mqtt user
  • set mqtt integration use the mqtt user+password

What might be causing this and how can I fix?
Some ESPHome configuration seems to be off?

2

what ESPHome builder version are you using?
there was an issue with 2026.6.0 which is fixed in 2026.6.1

3

Yes, I'm running ESPHome 2026.6.0. So let's see if 2026.6.1 helps. I'l report back soon and edit this message.

EDIT: No changes, still get the same log line every 5 seconds. @Krivatri

4

Ok, the reason seemed to be that I had an unconnected/powered off ESP32 device configuration updated and saved. And in that edit I added an incomplete mqtt configuration in the device yaml. So it seems that HA Esphome Builder uses those credentials even without the actual device.