Fronius + Daikin

What Zerofy can do with Fronius and Daikin

In practice

• Hot water is the simplest heat store: Autopilot can raise the hot-water temperature of your Daikin heat pump in hours with surplus.
• Zerofy can also change the room temperature and flow temperature of your Daikin heat pump, so space heating can shift into sunny hours.
• A heat pump draws roughly 1–3 kW while running, which a typical Fronius home system (3–10 kW) can cover on sunny days.
• Zerofy gets new Fronius data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Zerofy also shows your Fronius battery, so you can see whether surplus goes into the battery or into the heat pump.
• Check how your installer set up the flow temperature: with a weather-dependent curve, Onecta only allows shifting the curve with an offset, not setting a fixed leaving-water temperature. Raising the hot-water setpoint during surplus is usually the simplest way to store solar heat.

What Fronius and Daikin offer on their own

Fronius: The Fronius Ohmpilot feeds surplus into a heating rod (0.3–3 kW single-phase, 0.9–9 kW three-phase) and has a control output for a heat pump with an SG Ready input. GEN24 inverters can also switch an SG Ready input through one of their four digital outputs plus a coupling relay, and Fronius lists direct integrations with heat pumps from IDM, Bosch and NIBE.

Daikin: Altherma units have Smart Grid inputs driven by an inverter or energy manager: in “Recommended ON” the heat pump buffers PV power in the hot-water tank (optionally also in the rooms) and limits its power consumption, statically or dynamically from a pulse meter at the grid connection. With the BRP069A61 LAN adapter the meter must measure the net feed-in at a single grid connection point.

Zerofy connects the two: it reads Fronius production and controls your Daikin heat pump to match, together with your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up Fronius and Daikin in Zerofy

1. Connect Fronius

Zerofy reads your system from Fronius Solar.web through a guest account that you create for Zerofy.

1. Make sure your Fronius inverter is online and shows up in Solar.web.
2. In Solar.web, go to Settings → Permissions and create a new guest account.
3. Add Fronius in Zerofy and log in with the guest account credentials.

Step-by-step guide for Fronius

2. Connect Daikin

Zerofy connects to the Daikin Onecta cloud with your Onecta login and can set room temperature, leaving-water (flow) temperature and hot-water temperature; Autopilot runs it on solar surplus or low prices.

1. Register the heat pump or air conditioner in the Daikin Onecta app and check it is online.
2. In Zerofy, add Daikin and log in with your Onecta credentials.
3. Enable Autopilot (Solar or Smart mode) for the device.

Step-by-step guide for Daikin

3. Turn on Autopilot

In Zerofy, open your Daikin heat pump, turn on Autopilot and choose Solar – or Smart to also use dynamic tariffs and forecasts. Set the priority, activation threshold and minimum runtime.

Dynamic tariffs

Zerofy can also run your Daikin heat pump on dynamic electricity prices (EPEX Spot or Nord Pool, e.g. Tibber or aWATTar) or on a fixed time-of-use tariff. Smart mode combines those prices with forecasts of your household consumption and your Fronius solar production.

Learn more about Smart Mode

About Fronius and Daikin

Fronius – Austrian manufacturer of inverters, welding and battery-charging technology. Homeowners typically have a Primo GEN24 (single-phase, 3–6 kW) or Symo GEN24 (three-phase, 3–10 kW) hybrid inverter, older Primo/Symo SnapINverters, and the Fronius Reserva battery (6.3–15.8 kWh). Monitoring app: Fronius Solar.web.

Daikin – Daikin is a Japanese air-conditioning and heat pump maker with its European headquarters in Belgium. Homeowners typically have an Altherma 3 air-to-water heat pump or Daikin split air conditioners, both connected through the Daikin Onecta app. Products: Altherma 3 R, Altherma 3 H HT, Altherma 3 M, Altherma 3 GEO, split air conditioners in the Onecta app.

Manufacturer information last checked: October 2026.

All devices that work with Fronius