Smart Home Tips

Understanding SONOFF Detach Relay Mode: How It Works & Use Cases

Understanding SONOFF Detach Relay Mode: How It Works & Use Cases

Introduction

Smart lights and switches often lose connectivity when the wall switch is turned off—breaking automations and preventing remote control. SONOFF’s Detach Relay Mode solves this by keeping the smart relay powered even when the external switch is off, ensuring uninterrupted control and smarter use of traditional switches.

What is Detach Relay Mode?

Detach Relay Mode separates the physical wall switch from the relay. When enabled, the switch only sends a toggle signal—it does not cut power to the relay or light. This allows lights or relays to remain powered and online, even with the external switch turned off, making the switch act more like a trigger than a power cutoff.

What It Solves

1. Smart device power outages

In traditional wiring, when the wall switch disconnects power, smart devices (such as smart lights) are completely powered off and offline, making them uncontrollable via the app or automation. Detach Relay Mode ensures that even if a smart device is physically "turned off," it remains powered on—smart controls remain available.

2. Maintain family habits of using traditional switches:

Elderly, children, or visitors may prefer to use wall switches. By enabling this mode:
They can press the switch as usual;
You can still operate it remotely via the mobile app without interruption.

3. Transform a traditional switch into a "smart scene button"

By setting a scene, the external switch button no longer controls the load on or off, but instead acts as a trigger to execute a smart scene (such as opening curtains, turning off all lights, activating home mode, etc.).

Supported Devices

Product Model

Product Name

MINIR4

MINI Extreme WiFi Smart Switch

MINIR4M

MINI Extreme WiFi Smart Switch (Supports Matter)

MINI-D

MINI Dry WiFi Smart Switch (Dry Contact Relay)

ZBMINIR2

ZBMINI Extreme Zigbee Smart Switch (Neutral Wire Required)

ZBM5

SwitchMan Zigbee Smart Wall Switch (Supports both No Neutral and Neutral Wire)

These models support Detach Relay Mode, allowing the external wall switch and relay to operate independently—perfect for combining traditional switch behaviors with smart automation.

How to Enable the Mode

Find it in the eWeLink app→Device Settings→Detach Relay.

Real-World Use Cases

1. Smart Lights Behind a Traditional Switch

Detach Relay Mode is ideal when you want a wall switch to act only as a remote trigger—without directly powering the load. This is especially useful when the light is controlled by other smart automation or scenes within your ecosystem. The physical switch sends a signal, while the actual switching is handled virtually.

2. Multi-Gang Switch

If you're using a multi-gang switch, Detach Relay Mode allows them to be used purely as scene triggers—great for arming security systems, running routines, or toggling multiple devices with a single press.

3. Door Entry Systems

In smart access control systems, a wall switch set to Detach Relay Mode can act as a button to trigger door open/close commands or log an event without engaging any actual relay output—preserving the relay lifespan and increasing safety.

4. Smart Control in Shared or Rented Spaces

In offices, hotels, or rental homes, you may want users to have a tactile button without letting them control power directly. Detach Relay Mode lets the switch serve as an input while the logic stays securely managed in your automation platform.

For example, a user on Home Assistant forums shared how ZBMINIR2’s Detach Relay Mode works with Zigbee2MQTT to let the switch send "toggle" commands to HA while keeping the relay powered—ensuring smart bulbs stay online even if the wall switch is flipped off.

Conclusion

SONOFF’s Detach Relay Mode offers a smart, flexible approach for keeping your smart devices online—even when a physical switch is turned off. With supported devices like MINIR4, MINIR4M, MINI‑D, ZBMINIR2, and ZBM5, users can retain physical switch functionality while relying on app, voice, or automation controls to manage relays.

Whether you're automating lighting, building scene triggers in shared homes, or ensuring safety without compromising on control—Detach Relay Mode bridges traditional switches with modern smart home design, enabling reliable, automation-friendly behavior that fits seamlessly into your lifestyle.

Reading next

SONOFF is Heading to IFA 2025 – Explore the Future of Smart Living

Leave a comment

All comments are moderated before being published.

This site is protected by hCaptcha and the hCaptcha Privacy Policy and Terms of Service apply.