Hoymiles + CTC

What Zerofy can do with Hoymiles 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. A Hoymiles balcony system covers only a small part of that, a rooftop system (Hoymiles systems range up to 10 kW) much more on sunny days.
• Zerofy gets new Hoymiles data only every 15 minutes, so the heat pump reacts to clouds with some delay. A slightly higher activation threshold and a minimum runtime in Autopilot keep it steady.
• 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 Hoymiles and CTC offer on their own

Hoymiles: On the three-phase HiOne all-in-one storage system (G3), Hoymiles has a dry contact (DO1) for SG Ready heat pumps, but the manual (January 2026) lists heat pump control as “coming soon”. Hoymiles microinverters have no heating control.

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 Hoymiles 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 Hoymiles and CTC in Zerofy

1. Connect Hoymiles

Zerofy connects to the Hoymiles S-Miles Cloud with your S-Miles account and reads your PV production.

1. If your installer hasn’t set up your plant yet, register it in the S-Miles Installer app (use DIY mode if you install it yourself).
2. In Zerofy, add an inverter, choose Hoymiles and log in with your S-Miles credentials.
3. Use Autopilot (Solar Mode) to switch devices on solar surplus.

Good to know: Zerofy reads PV production only from Hoymiles, not grid meter or battery data, and stores the power history in 15-minute steps (5 minutes for most other brands).

Step-by-step guide for Hoymiles

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 Hoymiles solar production.

Learn more about Smart Mode

About Hoymiles and CTC

Hoymiles – Hoymiles (Hangzhou, China) is one of the largest microinverter makers. In Europe it is best known for balcony systems such as the HMS-800W-2T (switchable 600/800 W) with the MS-A2 balcony battery, and it also sells HYS/HYT hybrid inverters with home batteries. Monitoring app: S-Miles Cloud (S-Miles app).

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 Hoymiles