Device keeps switching back on after a minute

Configuration Zigbee
1

Hello all.
I am running Home Assistant 2022.11.2 on Docker on Ubuntu with, amongst other things, a Zigbee network.
All is working well but I have one device (my hot water controller) which is a Sonoff 01MINIZB that turns the hot water circuit on or off on a timer or an override binary button on my dashboard.

It works fine except that whenever I switch it off it switches itself back on again after a minute. The history simply says “Turned on” but doesn’t hint at what has turned it back on. See attached image.
I’ve tried running the log on debug which gives loads of data but I’m not sure how to interpret it as I can’t see anything obvious that is doing it.

No other devices do this, just the hot water switch. I have tried “reconfigure” of the device and several reboots of HA.

Is there a way I can find out what is turning it on after I have turned it off? Any help or pointers would be appreciated.

Mike

image

2

it means, it was turned by externally, neither by a HA user nor a service.

I don’t know what are the possibilities of external switching?

1 Like
3

Its either being turned on/off via the physical switch, or maybe you’ve got a power issue and the default start up state for the switch is ‘on’ (check your device settings to check this). Could it be drawing too much current given its connected to a water heater ?

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Thanks for that suggestion Rofo.
The hot water is a changeover (SPDT) connection so I’m using the Zigbee switch to fire a mains relay to do the changeover. Maybe the Zigbee switch doesn’t like switching a mains relay.

I’ll do some more digging but thanks for the pointers.
Mike

5

I think I have found out why it is doing it.
The switch controls a 240v SPDT relay because the HW switch is a changeover one. If I remove the 240v relay, the Zigbee switch works correctly. It could be something to do with back EMF from the relay which is triggering the Zigbee switch. It’s a little worrying as I assumed that the output of the Zigbee switch was isolated from the control circuits but maybe not so.
I’ve got around it by adding some logic so that when I send a “Off” command I then check after a second to see if it is actually off and then send “Off” again. It does this a few times in a row and that seems to turn it off. A bodge but what isn’t!

6

Have a similar issue. I put a sonoff relay in my coffee grinder.

Sonoff relay 01MINIZB

Occationally it turns on again after its done grinding. Sometimes it does not turn on.

Ive «hacked» it in sw as you did for the time being.

Im thinking back emf from the motor is causing some issues.

Thinking to try a pulse snubber across the motor to see if it becomes more reliable.
(220nF capacitor, 470 Ohm resistor)