Enphase + SG Ready

What Zerofy can do with Enphase 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, which a typical Enphase home system (3–10 kW) can cover on sunny days.
• Zerofy gets new Enphase data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Zerofy also shows your Enphase battery, so you can see whether surplus goes into the battery or into the heat pump.
• 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 Enphase and SG Ready offer on their own

Enphase: The IQ Energy Router+ (IQ Energy Router plus Energy Meter and SG Ready Relay) controls one SG Ready heat pump. It only uses SG Ready states 2 (normal) and 3 (recommended on), and Enphase publishes wiring guides for Daikin Altherma 3, Vaillant aroTherm plus and iDM.

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.

Directly, without Zerofy: Any SG Ready heat pump can be switched by the IQ Energy Router+, which includes the SG Ready Relay and an Energy Meter.

Zerofy is the alternative if you want Enphase, SG Ready and your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up Enphase and SG Ready in Zerofy

1. Connect Enphase

Zerofy connects to your system through the Enphase cloud: you log in with your Enphase Enlighten credentials and Zerofy reads PV production, meter (consumption) and battery data.

1. Make sure your system is online and you have an account on Enphase Enlighten.
2. In Zerofy, add an inverter, choose Enphase and log in with your Enlighten credentials.
3. Configure the meters: the grid meter as main meter (bi-directional or consumption), production as a sub meter of type production.

Step-by-step guide for Enphase

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 Enphase solar production.

Learn more about Smart Mode

About Enphase and SG Ready

Enphase – Enphase Energy (Fremont, California) makes microinverters: each panel gets its own IQ8 unit of about 300–330 VA, connected through an IQ Gateway. The AC-coupled IQ Battery 5P adds storage in 5 kWh steps, and everything is monitored in the Enphase App (Enlighten). Monitoring app: Enphase App / Enlighten.

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 Enphase