Hi everyone,
I am based in Germany and currently running a Mitsubishi Ecodan (14kW) with an FTC6 controller, integrated into Home Assistant. I also have a PV system and a FoxESS home battery.
Given the Central European climate (heavy cloud coverage in transition seasons) and our local energy market, maximizing PV self-consumption while avoiding grid-pull is crucial. Over the last few weeks, I’ve built a highly customized, local logic in Home Assistant to perfectly align the heat pump with my PV surplus while strictly protecting the compressor from bad behavior.
I wanted to ask if anyone here has built something similar or comparable, and maybe exchange some ideas?
Here are the core concepts of my current architecture:
1. Anti-Panic Starts (Delta T Management): > To prevent the compressor from escalating to 104 Hz during a cold start, my HA logic uses a smart binary sensor. It fakes a target temperature to keep the Delta T strictly below 11 Kelvin. The machine now modulates buttery smooth without extreme pressure peaks.
2. PV-Boost “Joker” with Battery Hysteresis: > I created a dynamic time-based PV-Boost (DHW to 55°C). Between 10:00 and 14:00, if PV power is >= 3.5 kW and Battery SOC is >= 60%, the system triggers the boost. To prevent a start-stop loop when a typical German rain cloud passes, the boost only aborts if the SOC drops below 50%. This 10% hysteresis shields the compressor from weather fluctuations.
3. Reboot Armor & Modbus Sequence: > I implemented strict from: 'on' triggers and 5-minute delays to prevent HA from accidentally killing an active heating cycle during a core restart or YAML reload. I also use a custom Watchdog that enforces a strict sequence (Modbus target first, Shelly relay second) to prevent logical short-circuits that usually force the FTC6 into 3-minute autonomous maintenance cycles.
The system is running incredibly well and the Ecodan stays in its sweet spot. Has anyone tackled the Ecodan logic in a similar way? I would love to hear about your setups or share my YAML if anyone is interested!
Cheers!