TSUN + SG Ready

What Zerofy can do with TSUN and SG Ready

In practice

• When there’s enough surplus, Zerofy switches the relay and the heat pump receives the SG Ready signal. How it reacts – for example by heating the hot-water tank to a higher temperature – is set in the heat pump’s own controller.
• A heat pump draws roughly 1–3 kW while running – more than many small TSUN systems (typically 0.8–3 kW) produce, so solar covers only part of its consumption.
• Zerofy gets new TSUN data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Set in the heat pump controller how many degrees the hot-water and heating setpoints rise in the boost state (“recommended operation”); the default differs by manufacturer. Fronius and Enphase only switch between normal and recommended operation, so the heat pump keeps its own minimum run times.

What TSUN and SG Ready offer on their own

TSUN: TSUN has no heat pump or heating-rod control in its product range.

SG Ready: Several inverter energy managers drive SG Ready directly: Fronius (GEN24 or Datamanager 2.0 with Smart Meter and a 12 V relay), SMA Sunny Home Manager 2.0 (relay or I/O module), Huawei EMMA, SolarEdge Home Load Controller or Smart Energy Relay, Sungrow SH-RT hybrids (built-in DO relay) and the Enphase IQ Energy Router+. Most of them switch on a fixed surplus threshold.

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

Setting up TSUN and SG Ready in Zerofy

1. Connect TSUN

Zerofy connects to the TSUN cloud with your TSUN Smart login and reads your inverter data.

1. Register your system in the TSUN Smart app.
2. In Zerofy, add an inverter, choose TSUN and log in with your TSUN Smart credentials.

Good to know: Only TSUN Smart accounts work (inverter IDs starting with Y); TSUN Home accounts are not supported. Battery and meter data are only partly available, depending on the system.

Step-by-step guide for TSUN

2. Connect SG Ready

Zerofy switches the SG Ready inputs through a smart relay such as a Shelly that you connect to Zerofy; Autopilot then sends SG Ready signals based on solar surplus and low electricity prices.

1. Have an electrician wire a smart relay (e.g. Shelly) to the heat pump’s SG Ready inputs.
2. Add the relay to Zerofy.
3. Configure the relay as SG Ready controller in the app and turn on Autopilot.

Good to know: SG Ready gives Zerofy on/off-style states, not temperature readings or setpoints. To use all four states, the relay needs two channels, one per SG Ready input.

Step-by-step guide for SG Ready

3. Turn on Autopilot

In Zerofy, open your SG Ready 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 SG Ready 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 TSUN solar production.

Learn more about Smart Mode

About TSUN and SG Ready

TSUN – TSUN (TSUNESS Co., Ltd., Suzhou, China, with a German office in Frankfurt) makes microinverters from 300 W single units to 3.3 kW 6-in-1 units. In Europe it is mainly found in 800 W balcony systems such as the TSOL-MS800, often combined with TSUN balcony storage (MSU2000, MSU4000Elite). Monitoring app: TSUN Smart.

SG Ready – SG Ready (Smart Grid Ready) is a label introduced in 2012 by the German Heat Pump Association (BWP) for heat pumps that an external controller can switch between four operating states via two contacts. It is a signalling convention, not a data protocol: the heat pump’s own controller decides how far to raise temperatures in the boost state. Products: Heat pumps with the SG Ready label (two potential-free control inputs), from many manufacturers.

Manufacturer information last checked: October 2026.

All devices that work with TSUN