# MP21ZD / MP31ZD (800 Series) — Firmware

**URL:** <https://forum.minoston.com/t/mp21zd-mp31zd-800-series-firmware/71>\
**Category:** Firmware & Drivers\
**Tags:** zwave-800, firmware\
**Created:** [October 26, 2026, 3:50am UTC](https://forum.minoston.com/t/mp21zd-mp31zd-800-series-firmware/71 "2026-10-26T03:50:50Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![MinostonCS](https://yyz2.discourse-cdn.com/flex050/user_avatar/forum.minoston.com/minostoncs/32/12_2.png) [@MinostonCS](https://forum.minoston.com/u/MinostonCS)\
**Post date:** [October 26, 2026, 3:50am UTC](https://forum.minoston.com/t/mp21zd-mp31zd-800-series-firmware/71/1 "2026-10-26T03:50:50Z")

</div>

Firmware for the MP21ZD and MP31ZD plug-in dimmers (800 Series, 908.42 MHz). This page lists the current release and how to flash it over the air (OTA) from your hub.

## 1. Current release

| Item | Value |
| --- | --- |
| Current build | V8.01 (build `V08R10P00H01`), file dated 2025-11-03 |
| Applies to | MP21ZD (ZW39SU), MP31ZD (ZW39M) — 800 Series |
| Does NOT apply to | MP21ZD 700 Series units |

## 2. Should you update?

Check your current firmware version first (Hubitat: device page; Home Assistant: Z-Wave JS device page). If your devices are working fine you don’t have to rush, but we recommend staying current: newer builds fix reported issues and improve network stability.

## 3. How to update (OTA)

**Hubitat Elevation**

1. Open the device page and click **Firmware** (Device Firmware Updater).
2. Select the downloaded `.gbl` file and start the update.
3. Do not unplug the device during the transfer (typically 2 to 5 minutes).

**Home Assistant (Z-Wave JS / Z-Wave JS UI)**

1. Open the device page and expand **Firmware update (OTA)**.
2. Upload the `.gbl` file and confirm.
3. Leave the device powered for the whole transfer.

**Other controllers**

Any Z-Wave controller with OTA support (Z-Wave JS UI standalone, Zooz Z-Station / Silicon Labs PC Controller) can flash the same `.gbl` file.

**SmartThings** does not support third-party Z-Wave OTA updates. If your device shows issues this build addresses, contact [ask@minoston.com](mailto:ask@minoston.com).

## 4. If something goes wrong

- **Update stalls** : leave the device powered; large transfers can take a few minutes.
- **Version unchanged after update** : run the update once more.
- **Device unresponsive** : unplug for 10 seconds, plug back in, and re-run the update. If it still won’t respond, exclude and re-include it.
- **Still stuck** : email [ask@minoston.com](mailto:ask@minoston.com) with your hub type and the firmware version shown before the update.

## 5. Download

The November 2025 build addresses an error reported on earlier builds. Use this one unless support directs you otherwise.

**[MP21ZD\_MP31ZD\_V8.01\_202511.gbl](https://forum.minoston.com/uploads/short-url/kMzBqn5IgFObD9oEfZDOzf1M2AE.gbl)** (current, 148,848 bytes)

- SHA-256: `dc5ee36c2dd12011787654520f22ce071e5d4ae91fb8444a9d6cb136fea503d1`

**[MP21ZD.gbl](https://forum.minoston.com/uploads/short-url/7ZK6UOeOANG9AufptIxAAw4jtn.gbl)** (earlier bundle, 165,777 bytes)

- Build version not labeled in the file name. This is a legacy bundle kept for reference only. Do not flash it unless support asks you to; the November 2025 build above replaces it.  
Official source: [minoston.com/pages/firmware-driver](https://minoston.com/pages/firmware-driver)

Questions? Reply below or email [ask@minoston.com](mailto:ask@minoston.com).