2 gang dimmer and rocker? (UK)

Hardware
1

Struggling to find something to control my bathroom light and extractor fan - currently each is on it’s own switch in a dumb 2 gang. Fan doesn’t have a timer.

I’d like a dimmer for the light (controllable from the wall), and for both to be controllable from HA.

Ideally Zigbee or wifi. I do have a neutral wire at the switch, if that helps at all. Can 1 gang of a 2 gang dimmer module be configured as a switch for the fan? Any other suggestions?

2

Not a simple cots solution and not cheap, but you can buy a single face plate dimmer and switch unit like this

https://www.elesi.com/sockets-switches/switches/dimmer-switches/dimmer-rocker-combos

Replace the dimmer module with this zigbee dimmer module ( i have currently 2 of these and work well both manual or HA controlled - slight 1 sec delay when turning on manually but you adjust to that). Edit: cant get it to show correct link. It is the SM323 you want not the one shown in the link image.

Then on your fan switch side, use a mini sonoff zigbee switch to allow switch or HA control of fan.

1 Like
3

Thanks a lot! I’d clocked those samotech dimmers, good to hear a real world review though. And yes, I was hoping there would be a less expensive and complicated way to achieve what I wanted, but never mind!

4

Unfortunately they don’t seem to make 2 gang dimmers, only switches. Hopefully your back boxes are deep enough to fit a couple of modules in there? If not then maybe forgo the dimming and have a double switch.

I have been using a Sonoff ZBMINI to control a fan for over a year now and its been great. I use a Xiaomi Aqara temp/humidity sensor in the bathroom and a HACS component called Generic Hygrostat to sense when the humidity jumps (shower, etc.). This feeds the automation below that switches the fan on when the light comes on but only switches the fan off if the Hygrostat is off.

alias: Control - Ensuite Fan
description: Ensuite Fan Control
trigger:
  - platform: state
    entity_id: binary_sensor.ensuite_hygrostat
  - platform: state
    entity_id: light.ensuite_light
condition: []
action:
  - choose:
      - conditions:
          - condition: or
            conditions:
              - condition: state
                entity_id: light.ensuite_light
                state: "on"
              - condition: state
                entity_id: binary_sensor.ensuite_hygrostat
                state: "on"
        sequence:
          - service: homeassistant.turn_on
            data: {}
            target:
              entity_id: light.ensuite_fan_8de724fe_on_off
      - conditions:
          - condition: state
            entity_id: light.ensuite_light
            state: "off"
          - condition: state
            entity_id: binary_sensor.ensuite_hygrostat
            state: "off"
        sequence:
          - delay:
              hours: 0
              minutes: 1
              seconds: 0
              milliseconds: 0
          - service: homeassistant.turn_off
            data: {}
            target:
              entity_id: light.ensuite_fan_8de724fe_on_off
    default: []
mode: restart

Hope this helps.

1 Like
5

Two additional suggestions:

  • Back box depth can be extended with faceplate spacers which bring the face place forward.
  • Control gear can be installed in the loft space above the ceiling rose, as long as it is in an enclosure. 3+CPC cable can then be used to connect into the existing rose. This may be better for the fan as this must have a multi-pole isolator switch.
1 Like