KNX climate: HVAC turns OFF when switching from OFF to HEAT (Airzone Aidoo / Hitachi)

[elmondogri]

When setting HVAC mode from off to heat, the unit turns on briefly, then goes back to off.

I am not sending ON manually — it is triggered automatically by the KNX climate entity.

After repeating the same action 2–3 times, it eventually works and stays on.

⸻

KNX Trace

heat (HA)
heat (Aidoo feedback)
on (Aidoo feedback)
off (Aidoo feedback)

⸻

Notes
• HA sends heat, power follows automatically
• Aidoo acknowledges (heat → on)
• Then immediately forces off

This suggests the device rejects an intermediate state when mode/power are not applied coherently.

⸻

Question

Has anyone encountered this behavior?

Any recommended way to:
• ensure consistent state updates
• control write order
• or avoid this issue with KNX climate + HVAC gateways like Aidoo?

Thank you!

[farmio]

Hi 👋!
This doesn't seem like a HA integration issue - if I understand correctly it sends a single telegram and the device doesn't react correctly every time. Have you tried to reach out to the devices customer support?

[elmondogri]

Thanks for your reply!

I understand your point, but I don’t think this is purely a device issue.

From what I can see in the KNX trace, HA sends a single mode change (heat), and Aidoo does react correctly at first:

• mode = heat
• power = on

But immediately after, Aidoo sends back:

• power = off

So something is causing the unit to reject or override the state right after accepting it.

Important details:

• This only happens when switching from OFF → HEAT
• If I repeat the exact same action 2–3 times, it eventually works and remains stable

I have added a screenshot of the group monitor to make it more clear.

Also, when performing the same actions from ETS, it works perfectly every time:

• first set mode = heat
• then set power = on

No unexpected OFF is triggered.

This makes me think it could be related to:

• timing between mode and power
• missing/unsynchronized KNX objects
• or a state mismatch between HA and Aidoo at startup

So I’m trying to understand:
Is there any known requirement for ordering or synchronization of:

• HVAC mode
• power state
• or other KNX objects (fan, setpoint, etc.)

when using KNX climate?

Or any recommended way in HA/KNX to enforce a consistent state when turning on HVAC?

Thanks!

[elmondogri]

I was able to identify the root cause more precisely.

The issue is related to the timing between KNX commands.

When sending:

HVAC mode (e.g. heat)
immediately followed by power on

the device behaves like this:

acknowledges heat
acknowledges on
then immediately sends back off

The unit does not have time to actually start.

As a workaround, I removed the ON/OFF write GA from the climate configuration, and I now handle ON/OFF via an automation:

trigger on mode write
wait ~100 ms
then send ON/OFF

With this approach, the system works reliably every time.

It would be great if the KNX climate integration allowed:

controlling write order
or introducing a delay between mode and power commands

to avoid needing this kind of workaround.

[farmio]

I'd still recommend to reach out to the device manufacturer so they can fix their application. After all

acknowledges on
then immediately sends back off

this doesn't seem to be expected behaviour to me.

There are generally no timing constraints for consecutive group actions in knx. Imho introducing integration-wide workarounds for shortcomings of specific devices would be quite a maintenance nightmare.

Apart from that, why does it use 2 independent datapoints for on/off (binary and mode)? Maybe you can just configure it differently so it works like you'd expect - like not using binary on/off but only mode as it includes OFF state anyway.

[elmondogri]

I 100% understand your point and you re right. The fact is that when the mode is turned off it also turns the unit off. If I the set the mode to heat without turning on the unit then I have the state as heat but nothing happens physically on the unit. Strange behaviors Le dim. 29 mars 2026 à 11:54, Matthias Alphart ***@***.***> a écrit :

…

*farmio* left a comment (XKNX/knx-integration#57) <#57 (comment)> I'd still recommend to reach out to the device manufacturer so they can fix their application. After all acknowledges on then immediately sends back off this doesn't seem to be expected behaviour to me. There are generally no timing constraints for consecutive group actions in knx. Imho introducing integration-wide workarounds for shortcomings of specific devices would be quite a maintenance nightmare. Apart from that, why does it use 2 independent datapoints for on/off (binary and mode)? Maybe you can just configure it differently so it works like you'd expect - like not using binary on/off but only mode as it includes OFF state anyway. — Reply to this email directly, view it on GitHub <#57?email_source=notifications&email_token=AE6KQPAWK2SOUWZFCDR7RFD4TD6FRA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIMJUHE4DCNZZG42KM4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L#issuecomment-4149817974>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE6KQPDRMDVGTKLIELYHVHL4TD6FRAVCNFSM6AAAAACW47N27WVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCNBZHAYTOOJXGQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>