Two masters on the same light

Integrating Hue takes five minutes. The bridge is discovered by itself, you press the round button, done.

Afterwards Kapfenberg holds 278 entities instead of 177, and Vienna 156 from 37 devices. Both local, no account, no cloud.

And afterwards the problem begins that no guide mentions: the bridge automates by itself.

First, the five minutes that can also go wrong

After the button press the bridge is ready for about 30 seconds. In Kapfenberg the first attempt failed — the window had already closed by the time the request went out.

The fix is not better timing but the reverse order:

Start the loop first, then press. Re-request every few seconds for one to three minutes. Then the button press does not have to land on the second.

In Kapfenberg it caught after 28 seconds; in Vienna on the first pass.

The actual point: the bridge has routines of its own

Hue motion sensors keep their logic in the bridge, configured in the Hue app. It keeps running even when Home Assistant is off. That is an advantage — and exactly for that reason a trap.

I read the routines straight from the bridge. Four of them, all active:

Routine	Room	daytime	evening
“motion sensor entrance”	terrace	dimmed, off after 10 min	from 18:00 bright, 5 min
“motion sensor garden”	garden	dimmed, 10 min	from 19:00 bright, 10 min
“entrance area”	garden hut	dimmed, 10 min	from 18:00 bright, 5 min
dimmer switch	—	the switch at the beach chair

Each sensor also has a darkness threshold, so it only switches when it is dark.

Use the same sensor in Home Assistant as well and you have two masters on the same light.

This does not show up as an error message. It shows up as a light that switches itself off “by itself”, or an automation that apparently does not take effect. Both get investigated in the wrong place — namely in Home Assistant.

The decision belongs before the first light automation

Two clean routes, and only two:

1. Switch the routines off in the Hue app and build everything in Home Assistant.
2. Leave them there and do not let Home Assistant touch those same lights.

If the logic moves, the rule is: disable, do not delete. Then the way back stays open if the rebuild turns out worse than the original.

And the pleasant part: the scenes stay in the bridge and can be called from Home Assistant. Only the triggering logic has to be rebuilt, not the light itself.

Three small things that cost time while building

Every sensor appears twice. Once as a device, once at room level. Both show the same value. Pick one form and stay with it — otherwise you will later be hunting for why something fires twice.

The names are swapped in several places, in both flats:

The name says	the routine actually controls
“motion sensor entrance”	the terrace
“entrance area”	the garden hut
“bedroom switch 2”	sits in the child’s room
“child’s room switch”	sits in the bedroom
“hallway sensor”	sits in the toilet

None of this was created by us; it comes that way out of the Hue app. Cosmetic — and when building automations it reliably leads you astray.

Do not go by the name, go by the room.

A Hue automation appears as a switch in Vienna. A routine created in the Hue app shows up in Home Assistant as a switchable object. Flip it by accident and you are not turning off a light but a piece of logic.

A suspicion that could be measured

In Kapfenberg two names existed twice: once as a Hue light, once as a Shelly relay. The obvious suspicion was that the relay supplies power to the Hue lamps. Home Assistant would then be listing lights as “on” that are in fact dark.

Measured instead of assumed:

	Shelly	Hue
beach chair	relay off, 0 W	two lights on, reachable
garden hut	relay on, 48.4 W	light off, reachable

The Hue lights are reachable while the relay is off. Had the Shelly taken their power away, they would be unavailable. The names merely overlap — and I know them as two different lamps.

The second time, when a light really did not respond, I no longer just observed but actively switched: Shelly on, power measured over fifteen seconds — 0.0 watts. Nothing hangs on that socket.

The Shelly is being renamed anyway. Two devices with the same name are no danger until somebody builds an automation.

And the real cause was mechanical

During the switching test something else stood out: Home Assistant issued the commands, the bridge accepted them — but the state reports came back delayed and inverted. After a switch-off it still said “on”, and after the following switch-on it said “off”.

I found it myself while the fault-finding was still running: a loose contact in the cable.

That fits the picture exactly. A lamp that sporadically loses its supply acknowledges Zigbee commands unreliably — and the bridge then reports the last intended state instead of the actual one.

Inverted or lagging states on a single lamp point at the power supply, not at Home Assistant.

What I’d suggest

1. Start the pairing loop before pressing the button. The other way round fails on thirty seconds.
2. Read out what your bridge already automates before you build your first light automation. I had four active routines sitting there without knowing it.
3. Pick one side. Sensors in the bridge or sensors in Home Assistant — both on the same lights is the reason for “it goes off by itself”.
4. When moving the logic, disable rather than delete. And leave the scenes where they are; you can still call them.
5. Go by the room, not the name. Swapped labels out of the app are the rule, not the exception.
6. With inverted states on a single lamp, look at the cable first.

So what?

Of all the integrations in these three flats, Hue caused the least work: local, no account, with rooms and scenes that Home Assistant adopted by itself — in Vienna, 36 of 37 devices were assigned to an area immediately.

The price is not in the manual, and it is not a defect but a property: the bridge is itself a small home automation system. It keeps working when yours fails. That is exactly what you want — until you forget that it does.

Two systems on the same light do not produce an error. They produce a behaviour you will take for an error for a week.