Protecting Your Smart Home from Itself

A Foundational Home Assistant Automation

Welcome to another post in my series on the foundational configurations and my second post on managing your cover entities. A truly smart home doesn’t just automate for convenience; it also acts as a guardian, protecting our physical devices from damage. Today, we’ll explore a simple but powerful automation that serves as a safety net, preventing an expensive and easily overlooked accident: damage to motorized blinds from an open window.

This type of protective automation is a core principle of good smart home design. It anticipates potential conflicts between devices and intervenes to ensure they operate safely. Other applications for this pattern could include preventing an HVAC system from running while windows are open, or disabling a smart plug for a space heater if a smoke alarm is triggered.

The Problem: Motorized Blinds vs. a Fresh Breeze

Living in Loja, Ecuador, we are blessed with a wonderful climate, and we love to keep our windows open. However, we also have motorized blinds and shades. A strong gust of wind coming through an open window can catch a fully or partially closed blind, causing it to billow and potentially damage the fabric or the motor.

The challenge is that our blinds can be controlled in many ways—through the Home Assistant dashboard, by voice command, or with their own physical remote controls. We need a solution that works as a universal safety override, no matter how the command to close the blinds is given.

The Solution: A Templated Safety Net

To solve this, I created a single, elegant automation that monitors all of our blinds. It uses a templating technique to create a universal logic that is both efficient and incredibly easy to maintain.

When it detects that any blind is closing too far while its corresponding window is open, it immediately intervenes and moves the blind back to a pre-defined safe position (in my case, 62%). It acts as a silent guardian, ensuring that convenience never leads to an accident.

How It Works

This automation is a perfect example of how to handle multiple, similar devices without repeating code.

1. The Efficient Trigger: The automation uses a numeric_state trigger for each blind. This is highly efficient, as the automation only runs at the precise moment a blind’s position drops below the safety threshold (62%).

2. The Centralized Map: The real power of this automation is in the variables: block. I’ve created a “map” (a dictionary) that links each blind’s trigger.id to its corresponding window sensor or sensors. This is the only section you need to edit when adding new blinds.

3. The Templated Action: Instead of a long choose block, there is a single, short sequence of actions.

• It uses the trigger.id to look up the correct window sensor(s) from the map.
• It checks if any of the covered windows are open.
• If, and only if, a window is open, it sends a command to set the position of the blind that triggered the automation back to the safe limit.

Because the automation triggers on the state of the blind itself, it works perfectly even when you use the physical remote control.

How to Implement This in Your Home Assistant

This automation is easy to adapt to your own home.

You can get the complete, up-to-date code from my GitHub repository:

View the Window/Blinds Safety Automation on GitHub

To get it running, follow these steps:

1. Copy the Code: Start by copying the complete YAML configuration for the automation.

2. Customize the Map: This is the most important step. In the variables: block, edit the window_map to match your entities.

• For each blind you want to protect, create an entry where the key matches the id you will give its trigger (e.g., dining_shades:).
• The value should be a list containing the entity_id(s) of the window sensor(s) for that blind.

3. Configure the Triggers: Create a numeric_state trigger for each of your blinds.

• Make sure the id: for each trigger exactly matches the key you created for it in the window_map.

4. Set the Safety Limit: You can change the safety limit by adjusting the below: value in the triggers and the position: value in the final action.

This automation is a simple, elegant, and powerful example of how Home Assistant can be used to create a safer, more reliable smart home. By thinking ahead and building in these kinds of safety nets, we can enjoy the convenience of automation without the risk of unintended consequences.

Do you have automations that protect your physical devices? Share your ideas in the comments below or on GitHub.