0xC LOG: Hacking My Sauna with Home Assistant
And Saving $1000!
Like most people who enjoy a good sauna session, I wanted the convenience of coming home after a long day of being on the slopes to a preheated sauna. Unfortunately, my sauna controller was "dumb," requiring manually pushing a button, which is kryptonite to Home Assistant power user like myself.
The manufacturer recently released a solution—but it came with a price tag of over $1,000 plus a subscription. GROSS! That’s when I decided to take matters into my own hands.
After scouring the Internet for a specific type of relay that would work in the Sauna’s electronics and Home Assistant, I turned my sauna into a smart, remotely start-able sauna. The process was surprisingly straightforward, once I found a relay that could take AC power, requiring just a little bit of technical know-how, a multi-meter, soldering iron and some time to put it all together properly.
Here’s how I did it:
I needed to implemented a relay in parallel with the power button to trick the controller board into believing the button was pushed
I needed to “vampire” some electricity from the controller board to power the relay.
However, the challenge was the only available power was 24 VAC
Certainly I could have converted it to DC, but I had limited space for the electronics and luckily found a relay that could take AC input
The relay also had a Zigbee radio on it, allowing it to be remotely triggered by Home Assistant
After soldering the relay circuit in parallel to the power switch and putting it all together, I had a remotely start-able sauna!
This project demonstrates how easily we can take control of technology and save money by bypassing expensive proprietary solutions. You don’t need to settle for what’s offered out of the box—many systems can be enhanced with simple DIY upgrades.
Now, after a day of skiing, I can open my Home Assistant app and have my sauna hot and ready by the time I get home. The total cost? $17 and a bit of creativity.
Whether you’re looking to hack your sauna or apply similar techniques to other home projects, this DIY approach is proof that smart solutions don’t have to come with a premium price tag and longtail subscription.
🔗 Subscribe to my Youtube channel here
Let me know what you think—and if you have topics or people I should feature, drop a comment! Let’s dig into the future.