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Switches & Relays (WHO = 1 & WHO = 4)

The MyHOME integration provides full control for on/off relay actuators, socket outlets, contactors, and appliance relays operating on OpenWebNet WHO = 1, as well as probe-less thermoregulation relays / towel warmers (F430/2, F430/4) operating on WHO = 4.

In v2, setup and management are 100% UI-first: switch relays are automatically discovered over the SCS bus, and entity types (such as distinguishing between a wall switch and a power outlet) are configured natively through Home Assistant's UI settings without manual YAML.

🚀 Auto-Discovery

When your gateway connects to Home Assistant:

  1. Dynamic Bus Discovery: The integration listens to OpenWebNet WHO = 1 relay commands and active addresses.
  2. Device Creation: Each physical relay actuator (WHERE = 1..99 or area/point addresses WHERE = 01..9999) is registered as a Home Assistant entity linked to your gateway device.
  3. UI Customization: You can rename the switch, assign it to an Area (e.g. Kitchen, Utility Room), and select a custom icon directly in the Home Assistant UI.

🔌 Displaying Relays as Outlets, Valves, or Appliances

In legacy configurations, distinguishing between an outlet and a switch required manual class: outlet YAML entries. In Home Assistant v2, this is handled natively in the UI using Home Assistant's "Show As" feature:

  1. Open Home Assistant and navigate to Settings → Devices & Services → Entities.
  2. Select your switch entity (e.g. switch.kitchen_counter_socket).
  3. Click the Settings (gear) icon.
  4. Under Show As, choose how you want the entity presented across your dashboards:
  5. Switch (Default): Standard relay, appliance, or heater.
  6. Outlet: Wall socket / plug load.
  7. Light: If the relay controls an external transformer or ballast.
  8. Valve: Irrigation or water shutoff valve.
  9. Click Update. Home Assistant immediately converts the entity representation across Lovelace dashboards, voice assistants (HomeKit, Alexa, Google Assistant), and automations.

⏱️ Native Hardware Bus Timers

Like MyHOME lights, physical SCS switch relays can run native hardware timers directly on the bus. This ensures that pumps, heaters, or ventilation relays turn off after the elapsed time regardless of whether Home Assistant is running:

action: myhome.turn_on_timed
target:
  entity_id: switch.bed_heating_pad
data:
  time: 1800   # Turn on and automatically turn off after 30 minutes (1800s)

🔥 Probe-less Thermo Actuators & Towel Warmers (WHO = 4)

Bathroom towel warmers and electric radiant relays are often wired to F430/2 or F430/4 thermoregulation actuators (WHO = 4, e.g. Zone 7, Actuator 1 → WHERE = 7#1) without a room temperature probe.

  • No Phantom Climate Entities (Safe Coexistence with Real Thermostats): Actuator-only Dimension 20 status frames (*#4*7#1*20*0/1##), pure-valve Dimension 19 status frames (*#4*7*19*0*0/1## on configured Z#N zones), and circulation-pump demand/release notifications (*4*4001*...## / *4*4002*...##) no longer spawn broken temperature-less climate entities. Configuring a per-actuator switch (WHERE = 7#1) prunes any temperature-less ghost climate entity on that zone while preserving any real thermostat that reports temperature or mode on the same zone; configuring a zone-wide switch (WHERE = 7) claims the entire zone unless climate: is also explicitly configured.
  • UI Configuration (Recommended): Navigate to Settings → Devices & Services → MyHome, click Add thermo actuator / towel-warmer switch (WHO 4) on your gateway, and enter WHERE (e.g. 7#1 for actuator 1 of zone 7, 7 for the whole zone, or 7#1#4#01 behind an F422 bus interface).
  • Direct Dimension 20 Control (turn_on_command / turn_off_command left blank): When left blank, Home Assistant sends *#4*7#1*#20*1## / *#4*7#1*#20*0## and tracks live relay state in real time from both *#4*7#1*#20*0/1## bus writes and *#4*7#1*20*...## status replies (plus state restoration across restarts). Although the public OpenWebNet WHO = 4 specification lists Dimension 20 as read-only, emulated gateway firmwares (F454, MH200N, F459, F460, F461) and real MyHomeServer1 hardware translate #20 writes onto the SCS bus ($0496813100\r / $0496813101\r; H4684 and MH200 drop Dimension 20 frames). If your gateway or actuator ignores direct #20 writes, bind paired CEN+ or WHO = 1 scenario triggers instead.
  • MyHomeServer1 (Home + Project "Towel Warmer"): On MyHomeServer1, bt_thermo_manager actively locks Home + Project Towel Warmer (BNTR) objects and immediately reverts direct *#4*Z#N*#20*1/0## bus writes unless towel.setSync is invoked by a Home + Project / Home + Control Scenario or Automation. Create two Scenarios (Turn Towel Warmer ON and Turn Towel Warmer OFF): important — when adding the Towel Warmer to a Scenario's action list in Home + Project or Home + Control, its default action state is OFF (*#4*Z#N*#20*0##); tap the Towel Warmer item inside the ON scenario's action list to toggle its target state to ON (or select a boost duration) before saving. Because app-only scenarios do not allocate an OpenWebNet Scene_Address entry in MyHomeServer1, bind the two scenarios to any of the following triggers (even when every visible wall switch plate is already in use) and enter the corresponding frames in turn_on_command and turn_off_command:
  • Unpopulated button slots on existing SCS modules (WHO = 25 CEN+, zero wall keys lost): 2-module pushbuttons (H4652/2, L4652/2, K4652M2, LN4652, KW8010/8011/13) fitted with a single-rocker keycap and flush 2-channel actuator-controls (H4672M2, LN4672M2, K4672M2L) mounted behind blind covers or in junction boxes expose unused button slots in Home + Project that can be bound to CEN+ scenarios (e.g. *25*21#1*21## for ON and *25*21#2*21## for OFF) without changing any physical wall keycap.
  • A single unwired relay terminal (WHO = 1, only 1 channel needed): Register one unwired output terminal on any multi-channel actuator (F411/4, F411/2, K8002L, etc.) as a light/socket in Home + Project (e.g. WHERE = 09 in a technical room) and trigger the ON scenario when 09 turns ON (*1*1*09##) and the OFF scenario when 09 turns OFF (*1*0*09##).
  • Zero-SCS-slot fallback (emulated_hue): If every button slot and relay terminal on the SCS bus is occupied, pair Home Assistant's built-in emulated_hue bridge as a local Philips Hue light (BN3L) in Home + Project and trigger the ON/OFF scenarios from that virtual light.
# Optional YAML equivalent in myhome.yaml:
switch:
  bathroom_towel_warmer:
    who: "4"
    where: "7#1"
    name: Bathroom Towel Warmer
    # Optional — required on MyHomeServer1 Home + Project BNTR Towel Warmers
    # (or on gateways like H4684 / MH200 that drop Dimension 20 writes):
    turn_on_command: "*25*21#1*21##"
    turn_off_command: "*25*21#2*21##"

🔄 Legacy YAML Note

Note

If you are upgrading from legacy v0.9 installations and still have manual switch: blocks in /config/myhome.yaml, please refer to the v0.9.4 Legacy Switch Documentation or the Legacy YAML Migration Guide. In v2, all switches are managed dynamically via Home Assistant's native registry.