Shelly Relay or Smart Plug Not Connecting

Shelly devices offer local-first smart home control with optional cloud features. This guide covers common connectivity and configuration issues.

Device Won't Connect to WiFi

Initial setup problems:

  • AP mode: New Shelly creates WiFi network "shelly-xxx" - connect to configure
  • Web interface: Navigate to 192.168.33.1 when connected to Shelly AP
  • Shelly app: Can also use Shelly app for Bluetooth setup (Gen2+ devices)
  • 2.4GHz only: Most Shelly devices only support 2.4GHz WiFi
  • Special characters: Avoid special characters in WiFi password initially
  • Factory reset: Hold button 10+ seconds until LED pattern changes

Device Goes Offline

Connection stability issues:

  • Static IP: Set static IP in Shelly settings or router DHCP reservation
  • WiFi signal: Check signal strength in device web interface
  • Eco mode: Disable eco mode if device needs faster response
  • Cloud vs local: Local control works even if cloud is down
  • Firmware: Update to latest firmware for stability fixes

Switch/Relay Wiring Issues

When relay doesn't control load:

  • Wiring diagram: Follow correct diagram for your setup (with/without neutral)
  • Load type: Configure for light, switch, or edge trigger mode
  • Button type: Set momentary vs toggle switch type in settings
  • Detached mode: Button can control WiFi independently of physical switch
  • Power metering: PM models show power - verify load is receiving power

Dimmer Issues

For Shelly Dimmer:

  • Minimum brightness: Set minimum brightness to prevent flickering
  • Bulb compatibility: Not all LED bulbs work well - test with incandescent first
  • Trailing/leading edge: Try different dimming modes for your bulbs
  • Bypass needed: Very low wattage loads may need bypass module

Home Assistant Integration

Local control with HA:

  • Shelly integration: Official integration auto-discovers Shelly devices
  • CoAP/REST: Uses local protocols - no cloud needed
  • Gen2 devices: Use different protocol - ensure HA is updated
  • MQTT: Alternative: enable MQTT in Shelly for custom setups
  • Scripts: Gen2+ devices support local scripting