Limit non persistent and Limit persistent showing the same value in Home Assistant

[jvdbrg]

What happened?

Hi guys,

First of all thanks for the great work!

I'm using OpenDTU in combination with Home Assistant to achieve "zero export" and its working great for the most part.

I have only one issue while doing this and that is that in Home Assistant (or MQTT for that matter), while using the "Limit Non Persistent Relative Value" the "Limit Persistant Relative Value" (and the "Limit Persistant Absolute Value") also changes to the set value.

This is also the case when i change this value in OpenDTU directly.

Im kind of worried because im not really sure if this is just a display bug. If it's just a display bug then there is not really an issue but if it's really changing the Persistant value that that means the EEprom will weare out rellay fast.

Would you please be so kind to investigate?

To Reproduce Bug

Change the Non Persistant Value using Home Assistant

Expected Behavior

Only the Non Persistant Value should change.

Install Method

Pre-Compiled binary from GitHub releases

What git-hash/version of OpenDTU?

[v26.3.30]

What firmware variant (PIO Environment)?

generic_esp32

Relevant log/trace output

Anything else?

No response

Please confirm the following

• I believe this issue is a bug that affects all users of OpenDTU, not something specific to my installation.
• I have already searched for relevant existing issues and discussions before opening this report.
• I have updated the title field above with a concise description.
• I have double checked that my inverter does not contain a W in the model name (like HMS-xxxW) as they are not supported.

[frajop]

Same here

[heinzcarstens]

same here

[dermeb]

Same here — I also suspect it’s just a display issue.
Based on my testing, “Limit Non Persistent Absolute Value” appears to modify only the non‑persistent value and not the dangerous persistent one.

I changed the persistent value directly in openDTU, then set the non‑persistent value via Home Assistant, restarted the inverter, and after the reboot it reverted to the persistent value instead of the one set through HA.

[tg-github]

Adding a data point that may help narrow this down, since I tested it slightly differently than the original report.

Setup: Hoymiles HMS-1600-4T, controlled via OpenDTU [https://github.com/tbnobody/OpenDTU/commits/da0b663] and Home Assistant, with the goal of zero/near-zero export (same use case as the original report).

Test 1 — confirming the persistent value works as expected:

• Set the limit to 50% via the OpenDTU web UI using "Set limit permanently".
• Triggered an inverter restart via OpenDTU's own restart function.
• Result: inverter came back reporting 50% / 800W, as expected.

Test 2 — non-persistent value via Home Assistant:

• With the persistent value still at 50%, set the limit to 100% via Home Assistant, writing to the "Limit NonPersistent Relative" entity (intended to be RAM-only).
• Triggered the same OpenDTU restart function again.
• Result: inverter immediately came back reporting 100% / 1600W — i.e. the supposedly non-persistent value survived the restart instead of falling back to the 50% persistent value from Test 1.

Test 3 — ruling out Home Assistant/MQTT as the cause:

• To check whether this is specific to the HA/MQTT path, repeated the test using only OpenDTU's own web UI: explicitly used "Set limit temporarily" (not "permanently") to set 100%.
• Triggered an inverter restart via OpenDTU again.
• Result: identical to Test 2 — inverter came back at 100% / 1600W. This confirms the behavior is reproducible purely through OpenDTU's own UI, with no Home Assistant or MQTT involved.

Open question / next test:
All restarts above were triggered via OpenDTU's "restart inverter" function, which may only perform a soft reboot of the inverter's microcontroller rather than a true power cycle. I haven't yet confirmed whether the same "sticky" temporary value survives an actual overnight loss of DC supply voltage (genuine cold start at dusk/dawn) — that's the next test I'll run, and I'll report back with the result.

If it helps, I'm happy to provide more detail on request.

[github-actions]

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