A simple DIY project for peace of mind when you have an old electric stove. Let’s build a smart stove left on alert.

It’s a feeling I know all too well. You’re out of the house—maybe at the grocery store, maybe on your way to work—and a sudden, cold spike of panic hits you: Did I leave the stove on? Your heart does a little flip. You try to remember turning it off, but the memory is fuzzy. It’s the worst, right? For those of us with older, non-smart appliances, there’s no app to check for peace of mind. But what if you could build your own stove left on alert system? It’s easier than you might think, and you don’t need to be a master electrician to do it.

I found myself thinking about this recently. My electric stove is a trooper, but it’s decidedly old-school. It has knobs, heating coils, and zero digital smarts. While simple is often good, the lack of an auto-off or any kind of warning feature can feel like a risk. So, I looked into how to bring a little smart home magic to this vintage appliance, and it turns out, there are some great solutions for creating a reliable alert system.

Why Bother with a Stove Left On Alert?

Let’s be honest, a brand new smart stove is expensive. If your old one still works perfectly fine, it’s hard to justify the cost. This is where a DIY stove left on alert comes in.

• Peace of Mind: This is the big one. The ability to get a notification on your phone if your stove has been on for, say, more than 20 minutes is incredibly reassuring. No more derailing your day with a trip home just to check.
• Household Safety: An unattended stove is a significant fire hazard. An alert system protects not just your property but everyone in the house. It adds a layer of safety that older appliances just don’t have.
• A Fun Smart Home Project: If you’re already dabbling with platforms like Home Assistant, this is a practical and rewarding project that solves a real-world problem.

Exploring Solutions for Your Alert System

So, how can a smart home system know if an old stove is on? It boils down to detecting one of two things: the position of the knob or the electricity it’s using.

While there are products that fit over your stove knobs and buzz after a set time, they aren’t “smart.” They can’t send a notification to your phone when you’re not home. For a true smart solution, we need to look at energy monitoring. This is the most reliable method because a stove burner, when it’s on, draws a very predictable amount of power.

This approach is perfect for a smart home setup. The basic idea is to monitor the electric current going to the stove. When the power draw jumps up and stays up, your system knows the stove is on and can start a timer.

Building a DIY Stove Left On Alert with Home Assistant

This is where the fun begins. If you’re using a platform like Home Assistant, you can create a powerful and customized stove left on alert with just one key piece of hardware: a current sensor.

Disclaimer: This project involves working near your home’s electrical panel. If you are not 100% comfortable and knowledgeable about electrical safety, please hire a licensed electrician. It’s a quick job for a pro. For more information on electrical safety, check out the resources from the Electrical Safety Foundation International (ESFI).

Here’s the simplified game plan:

1. Get a Current Clamp Sensor: The secret ingredient is a device called a “current clamp” or “energy meter.” Products like the Shelly EM are popular for this. The device has a C-shaped clamp that you simply snap around one of the hot wires powering your stove at the breaker box. You don’t have to cut or splice any wires, which is what makes this a relatively safe DIY project.

2. Integrate with Home Assistant: Once installed, you connect the sensor to your Wi-Fi network. Home Assistant can then discover it and start pulling in data. You’ll get a new sensor entity that shows you exactly how many watts your stove is using in real-time.

3. Create the Automation: This is the brain of the operation. In Home Assistant’s automation editor, you set up a simple rule. It looks something like this:

   • Trigger: When the stove’s power sensor reports a value above 200 watts for 20 minutes. (You can adjust these values based on your stove).
   • Action: Send a notification to your phone. You can even get creative!
     • Flash a specific light in the house.
     • Have a smart speaker announce, “The stovetop has been on for 20 minutes.”
     • If you’re away from home, send a critical alert that bypasses your phone’s silent mode.

And that’s it. For a small investment in an energy monitoring device, you’ve given your trusty old stove a modern brain. You’ve created a safety net that brings not just convenience, but true peace of mind. Now, when that fleeting moment of panic strikes, you can just wait for the notification that doesn’t come, and know that everything is okay back at home.