Flow Randomly stops working

Hi New to homey so i setup a flow for my WC with a motion sensor and ikea light bulb

it works most of the time but some times it do not work and the light wont turn on.

Flow is
When this Zone is active

Turn on all the units on (changed the units to all the lights)

anyone one know why this is happening ?

What motion sensor?

Exactly when?

as a clairvoyant I think it is best to start reading here

i use the Aqara motion sesnor with an ikea light bulb.

to say exactly when is hard casue for me it seems random- it works fine maybe 2-3 times in a row then it stops and fails.

You have to be methodical about this:

  • does the motion sensor work?
  • does Homey activate the zone correctly?
  • does the light work?

To find out if the motion sensor works, create a flow: “WHEN motion is detected THEN write a message to the timeline”.

Run that flow for a few days to see if it always detects motion. If it does, change the flow to “WHEN this zone is active THEN write a message to the timeline”.

And again, run that flow for a few days.

When both those flows work as expected, it’s time to suspect an issue with the light.

By the way, what does “all units/lights” mean, specifically? How many devices are you switching?

Also, because you’re using Zigbee, you need to be aware of all the Zigbee pitfalls related to Homey (the limited amount of Zigbee devices Homey can control, interference between Zigbee and WiFi, etc).


What I thought was about the „Blind time“ of motion sensors. So if you go out of the WC and quickly go in again, it could be that the motion sensor didn’t recognize you because the blind time is still active.


Good point, the Aqara motion sensor has a default blind time of 60 or 90 seconds.

@robertklep What do you mean by “ blind time”?

When I look in the settings of the aqara motion help text states:
But this does bot seem to be a blind time (at every movement the internal timer will be restarted.

@siggajones please also share your flows that turn off the light.
The combination of the setting and your off flow can still cause issues:

Suppose the setting is 300s and your flow switches off the light after 1min:
1 motion switches on the light
2 your off flow switches off the light after 2 min
3 the motion sensor will still stay in the “motion detected” state for 300s (=5min)
4 so if you enter the room after 4 minutes:

  • motion sensor is still in “active” state and.
  • therefore zone activity is still in active
  • so the light will not turn on! Only thing that happens is the 300ms timer will reset
    So the zone

The amount of time the sensor is “blind” (insensitive) to motion after last detection. In other words, when it detects and reports motion, it will not report new motion until after the blind time has expired.

Correct, this setting sounds like something else.

This is the blind time.
Set it to 60s to have the “quickest” response.
Blind time is probably only to save battery.

So, when you keep the light on for 65s / 125s / 185s and use a Homey timer, the light should not be switched off if you keep moving around :grin:

You can (or could…) “hack” the Aqara sensor, then you can set the blind time to 5s.

Example flows

The “replace timer” part is the trick, if there’s a motion detection before the timer has finished, it re-starts again.

If its “blind time” or not depends on how you build your flows.

  • if your light is switched off based on a timer after zone active. Then this time is blind time. (Since the zone will stay active even if the timer has passed, so ot will not trigger again)

  • if your light is switched off based on a timer after zone inactive. Then its not blind time. (Since the zone is already inactive during this time, so motion will trigger the zone activity)

PS: make sure you cancel the timer when the zone becomes active again and the timer is on. (Zone de-active will restart the tomer)

It’s really funny. Experienced homey users intensively discuss one of x possible reason, while only very little is known about the actual problem.
@siggajones, it’s your turn. Give us more information, as @Dijker has already requested. Share your flows. How many Zigbee routers are in use? And so on, and so on…