Radiator Fan Controller

Blueprints Exchange
1

Control your radiator fans automatically based on temperature with hysteresis and optional window monitoring!

Version: 1.0.1

Import Blueprint

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GitHub Repository: GitHub - HubEight/home-assistant-blueprints: Collection of Home Assistant automation blueprints

Features

:white_check_mark: Temperature-based control with hysteresis to prevent rapid switching
:white_check_mark: Flexible temperature settings: Direct input or dynamic via input_number helpers
:white_check_mark: Multi-window support: Optional monitoring of unlimited window sensors
:white_check_mark: Safety features: Automatically turns off fan when sensor fails or any window opens
:white_check_mark: Smart startup: Checks conditions when Home Assistant starts or automation is enabled

How it Works

  • Fan turns ON when radiator temperature reaches your set threshold (default: 30°C)
  • Fan turns OFF when temperature drops below the lower threshold (default: 28°C)
  • Fan turns OFF immediately if any window is opened
  • Fan evaluates conditions when windows close or Home Assistant restarts

Configuration

Required:

  • Temperature Sensor: Sensor measuring radiator temperature
  • Fan Switch: Switch or smart plug controlling the fan

Optional:

  • Temperature ON (°C): Set direct value or use input_number helper
  • Temperature OFF (°C): Set direct value or use input_number helper
  • Window Sensors: Select any number of window/door contact sensors

Temperature Control - Two Options:

Option 1 - Direct Input (Simple):

  • Set fixed values: e.g., ON at 30°C, OFF at 28°C
  • Best for static setpoints

Option 2 - Input Number Helpers (Advanced):

  • Use input_number entities for dynamic control
  • Change temperatures on-the-fly via UI or other automations
  • Helper values override direct input if set

Example Use Cases

  • Single Room: Control a radiator fan to improve heat distribution
  • Multiple Rooms: Create separate automations for each room
  • Energy Saving: Stop heating when windows are open
  • Dynamic Control: Adjust temperatures based on time of day or other conditions

Installation

Method 1: One-Click Import

Click the import badge above!

Feedback Welcome!

This is my first blueprint contribution. Please let me know if you find any bugs or have suggestions for improvements! :slightly_smiling_face:

2

Thanks for your blueprint.

Here is my scenario: Hot Air panel on roof, two vents contrlolled by Sonoff iFan04 flashed with Tasmota fw. I couldn’t control 2 fans simultaneously, so I edited yaml this way:

fan_switch:
      name: Fan Switch
      description: Switch or outlet controlling the radiator fan
      selector:
        entity:
          filter:
          - domain:
            - switch
            - fan
          reorder: false
          multiple: true

Now I can control them, but I don’t know how to set speed of fans. The iFan04 allows setting three fan speed levels - low, medium, and high.

Any ideas how to set desired fan speed level?

3

Solved in automations


actions:
  - action: fan.set_percentage
    metadata: {}
    data:
      percentage: 66
    target:
      device_id: 116653b3528e131f9c2cffec3e41e48b
  - action: fan.set_percentage
    metadata: {}
    target:
      device_id: cfce5f9e3e3007e7cb04e916af66c776
    data:
      percentage: 33