FoxESS + CTC

What Zerofy can do with FoxESS and CTC

In practice

• Hot water is the simplest heat store: Autopilot can use the hot-water boost of your CTC heat pump to heat water in hours with surplus.
• A heat pump draws roughly 1–3 kW while running, which a typical FoxESS home system (2.5–15 kW) can cover on sunny days.
• Zerofy gets new FoxESS data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Zerofy also shows your FoxESS battery, so you can see whether surplus goes into the battery or into the heat pump.
• If you use CTC’s own spot-price control in myUplink, its “Blocking” at high prices can lower the hot-water setpoint; check that the CTC price limits and Zerofy’s Smart mode don’t pull in opposite directions.

What FoxESS and CTC offer on their own

FoxESS: FoxESS has its own R290 heat pumps (HP Series monobloc, HP BOX hydro module), controlled in FoxCloud 2.0, which lists a solar heating feature. The three-phase H3 Pro can switch an SG Ready heat pump through its dry contacts when feed-in exceeds a set start power.

CTC: CTC controllers have SmartGrid inputs (terminals K22–K25, a SmartControl wireless accessory or BMS): when an inverter or energy manager closes both contacts (“SmartGrid Overcapacity”), the controller raises the room/flow setpoint by 1–5 °C and the hot-water setpoint by up to 30 °C. Through myUplink, CTC can also download spot prices and switch between “Low price” and “Blocking” on its own.

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

Setting up FoxESS and CTC in Zerofy

1. Connect FoxESS

Zerofy connects to the FoxESS cloud: you log in with your FoxESS Cloud account and authorize access on FoxESS’s own screen.

1. Make sure your inverter is online and registered in the FoxESS Cloud app.
2. In Zerofy, choose FoxESS and log in with the FoxESS Cloud owner account.
3. Confirm your devices on the FoxESS authorization screen.

Good to know: Use the owner account of the device. Installer and agent accounts don’t own the devices, so FoxESS shows “No Devices” and the connection fails.

Step-by-step guide for FoxESS

2. Connect CTC

Zerofy reaches CTC heat pumps through the myUplink cloud, the same connector used for NIBE, with your myUplink login; Autopilot controls the hot-water boost.

1. Connect the heat pump to the internet and register it in the myUplink app.
2. Make sure your myUplink account has the subscription needed for remote control.
3. In Zerofy, connect myUplink and log in with your myUplink credentials.
4. Enable Autopilot (Solar or Smart mode) for the hot-water tank.

Good to know: Zerofy steers only the hot-water boost on CTC units, not room or flow temperature.

3. Turn on Autopilot

In Zerofy, open your CTC 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 CTC 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 FoxESS solar production.

Learn more about Smart Mode

About FoxESS and CTC

FoxESS – Fox ESS is a Chinese inverter and storage maker founded in 2019 and headquartered in Wenzhou. Homes typically have the single-phase H1/AC1 (2.5–6 kW) or KH (7–10.5 kW) hybrid inverters or the three-phase H3 Smart (5–15 kW), with EP, EQ or ECS batteries. Monitoring app: FoxCloud 2.0.

CTC – CTC is a Swedish heat pump maker from Ljungby. Its air-to-water, ground-source and exhaust-air heat pumps and EcoZenith indoor modules are controlled remotely through the myUplink app. Products: CTC EcoAir, CTC GS/GSi 600, CTC EcoZenith i255/i360/i555 Pro, CTC EcoPart i600M, CTC EcoVent i360F, CTC EcoLogic L/M.

Manufacturer information last checked: October 2026.

All devices that work with FoxESS