I’m an independent developer with a passion for automation. I firmly believe that manual tasks are the root of all evil, especially when they can be automated. Let’s face it: life’s too short to waste time on things that machines can handle. This philosophy led me to optimize my home heating system and eventually develop a service to do the same for others.
From old-school hacks to modern automation
It all started with my trusty old heat pump from Swedish CTC, which had been loyally heating our house for over 20 years. This old beast had a feature called night setback, which added a negative offset to the leaving water temperature based on a heating curve relative to the outdoor temperature. To trigger the feature, you had to short two terminals on the control board. Naturally, I rigged up a relay and a microcontroller connected to my home server to automate the whole process. Simple, right?
But like all good machines, the CTC pump eventually started to give out. It was time for an upgrade, and after some research, I ended up with a Daikin Altherma 3. Why? Because it had the ONECTA app and an integration interface that promised automation bliss.
Reverse engineering for fun (and friends)
Once my shiny new Daikin Altherma 3 was installed, I did what any automation nerd would do: I reverse-engineered the ONECTA app. This gave me control over my heat pump and allowed me to optimize it based on energy prices. Pretty soon, friends on X (formerly Twitter) started asking if I could do the same for their heat pumps.
That’s when things really took off. Earlier this year, Daikin released their official integration API, and I was finally able to turn my side project into a full-blown service that anyone with a Daikin heat pump could use.
Heating smarter, not harder
So, why bother optimizing your heating? Well, energy prices fluctuate like crazy these days, especially if you’re with a utility company that offers hourly energy rates based on Nord Pool’s energy exchange. The goal was simple: heat my home when prices are low, and keep it comfortable (without cranking up energy use) when prices are high. This way, my family stays warm, and I don’t get nagged about letting the temperature drop too much.
The result? A smart heating system that works with real-time pricing, heating more when it’s cheap and easing off when energy prices skyrocket. It’s all about spending energy—and time—wisely.
My setup in Stockholm, Sweden
- Daikin Altherma 3 10kW geothermal heat pump
- Daikin Madoka wired room thermostat (and remote control)
- Central heating our 1930s home through radiators.
Automating while staying in control
To really dial in the system, being able to configure the leaving water offset and target room temperature min/max is essential for ensuring the right balance between efficiency and comfort in any home.
With these settings, the smart grid for Daikin controls the system, keeping my home warm enough without wasting energy, maintaining comfort, and keeping costs in check.
What’s next? Going official!
Now that Daikin has an official API, I’m gearing up to offer this service to the masses. The goal? Help others save on energy bills without having to lift a finger. By combining Daikin’s tech with Nord Pool pricing, anyone can optimize their heating system and reduce their energy costs.