How to connect Stiebel Eltron heat pump with Reduxi Gateway
Save up to 30% on energy costs: use the SG-ready contacts of your Stiebel Eltron heat pump via the Reduxi Gateway. Dynamic control follows fluctuating energy prices.
1 Technical documentation
Manufacturer documents for Stiebel Eltron heat pumps:
- Stiebel Eltron heat pumps – Product information on the manufacturer website
- Instruction manuals – Installation and operating manuals of the heat pump
- Downloads – Further documents and downloads from Stiebel Eltron
2 Required equipment
Two components connect the Reduxi Controller to the Stiebel Eltron heat pump:
- Reduxi Controller
- Reduxi Gateway device with 3x (30:1A) current sensors (CTs)
- Laptop or tablet with internet access to configure the device in Reduxi
Add the Reduxi Gateway device to the Reduxi Controller first. Only then you can control the operation modes of the heat pump. The connection is wireless (WLAN) or wired via a UTP cable (LAN). More information: Gateway to Controller connection.
The Reduxi Gateway device has two functions:
- Its 3x (30:1A) current sensors (transformers) measure the electrical current, and so the power, of each phase of the heat pump.
- Its two relay outputs generate the signals for the SG-ready contacts. The signals change the operation mode of the heat pump.
3 Connect the Reduxi Gateway to the heat pump
3.1 Overview of the connection
The picture shows the entire connection from the Reduxi Controller to the heat pump.
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Diagram of the connection between the Reduxi Controller and a heat pump. Components: Controller (dark Reduxi box with a green display and an Ethernet port on its front); a router icon with Wi-Fi symbol; Heat pump (outdoor unit with fan and an SG Ready badge at its left); Gateway (Reduxi Gateway box with three blue current sensors attached). Teal lines: Controller to router labelled "Ethernet (Modbus TCP)"; router to Gateway labelled "Ethernet (Modbus TCP)" with the note "Wireless or wired" under the router; Gateway to the SG Ready contacts of the heat pump (line from the Gateway up to the SG Ready badge); a vertical line from the Gateway to the heat pump labelled "L1, L2, L3"; a line from the current sensors to a teal box "Heat pump power supply".
Further information on connecting the Reduxi Gateway device: How to configure Reduxi Gateway.
3.2 Connect the relays to the SG-ready contacts
First find the SG-ready contacts on the circuit board of the heat pump. They are on the X1.13 connector. The first image shows the location. The second image shows the connections from the relays to the SG-ready contacts.
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Photo of the open control unit of a heat pump with a circuit board. In the upper part a row of green, red, blue and beige screw terminal blocks with wires and printed labels below them (some readable: X1.6, X1.7, X1.9, X1.10, X1.11, X1.12, X1.13, X1.14, X1.15). One terminal block labelled X1.13 with a thin wire in beige and brown is marked with a blue rectangle. In the middle a transparent cover with a green lit strip and rows of relays; in the lower part terminal blocks labelled X2.1 to X2.12 and others with wires. A grey cable runs from the right side of the board downwards. Grey wall at left, white device housing at right.
| Reduxi Gateway device | Contact on X1.13 connector | Wire |
|---|---|---|
| NO contact of the first relay | First contact | Black |
| COM contact of both relays | Second contact | Brown |
| NO contact of the second relay | Third contact | White |
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Photo montage of a connection from a Reduxi Gateway device to a heat pump terminal strip. Left: a dark grey Reduxi Gateway box (print reduxi Gateway) with a black plug-in connector with several wires on its front edge. Right: photo of a terminal strip with labelled terminal blocks: X1.10, X1.11, X1.12 (black blocks), X1.13 (beige block, wires inserted at the top), X1.14, X1.15 (pink blocks), X1.16, X1.17 (blue blocks); a further label to the left is cut off (ends in 9). Three coloured lines are drawn over the photo from the gateway connector to the beige terminal block X1.13: a white line, a black line and an orange line. The exact terminal each line ends at is not clearly visible.
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Diagram on a white background with the title "A normally closed (NC) contact/switch". Upper part, heading "Normal state": a switch drawn with the lever lying on the right circle, so the circuit is closed. Lower part, heading "When activated or pressed": the lever is raised, open between two circles, so the line is broken.
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Diagram on a white background with the title "A normally open (NO) contact/switch". Upper part, heading "Normal state": a switch drawn with the lever raised, open between two circles, so the line is broken. Lower part, heading "When activated or pressed": the lever lies down on the right circle, so the circuit is closed (partly cut off at the bottom of the image).
3.3 Connect the current sensors
The current sensors measure the current of the heat pump. They provide real-time data on its power consumption. Voltage readings come from the Reduxi Controller. If they are not available, a default voltage of 230 V is used.
Connect the three current sensors (CTs) of the Reduxi Gateway kit to the three inputs, one for each phase, as shown below.
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Diagram (rendered product picture) of a dark grey Reduxi Gateway box, label "reduxi GATEWAY" on top. On its front side a terminal block with printed labels GND, PORT 1 (A, B), PORT 2 (A, B), 5V, and three round sockets labelled I1, I2, I3. Three blue split-core current sensors with black cables are plugged into I1, I2 and I3; the cables hang down in loops in front of the box.
Each current sensor covers one phase wire (L1, L2, L3) of the heat pump.
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Photo looking into an open blue metal cabinet. Three blue split-core current sensors are stacked at the left, each placed around a conductor. Around them are many cables: white, grey, blue, yellow-green and black wires, blue network cable, an orange wire connector in the middle and a terminal strip at the lower right. Floor tiles are visible at the lower left. No text or markings are legible.
4 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
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Screenshot of three Reduxi mobile app screens side by side, with cyan boxes and number badges 2 to 4. Left screen (dashboard, dark theme): menu icon at top left marked with a box and badge 2; 'reduxi' logo; tabs 'Real time data' (active) and 'Statistics'; price 5.79 € and temperature 3.2 °C; energy flow diagram with a house in the centre (-1.25 kW) and icons with values 69.0 W, 1.3 kW, 1.1 kW (red ring), -165.0 W with 97 % (red ring) and 0.0 W values at the bottom; tabs 'Power' and 'Energy'; bottom navigation: Dashboard, Diagnostics, Device control, Settings. Middle screen (side menu): 'reduxi' logo, 'Number of locations: 1233', heading 'Reduxi device management', entries '+ Add Reduxi location' and 'Reduxi devices' (marked with a box and badge 3), then 'My profile' and 'About app'. Right screen (device page): Back; picture of a black Reduxi controller with two Ethernet ports; status 'Connected'; card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'; card 'Connect to configurator': 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' with button 'Activate tunnel connection' (marked with a box and badge 4); card 'Unit details' with field 'Unit ID'.
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Screenshot made of two parts side by side. Left part: Reduxi mobile app screen on a dark background. Top: Back button; picture of a black Reduxi controller with two Ethernet ports and a terminal block; status 'Connected' with a Wi-Fi icon. Card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'. Card 'Connect to configurator' with a key icon: 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' and button 'Open configurator', marked with a cyan box and number badge 5. Below: card 'Unit details' with a field 'Unit ID' (value not visible). Right part: Reduxi Configurator opened in a browser, marked with a cyan frame and number badge 6. Header: back arrow, 'Tunnel connection', reload icon. Left sidebar with icons (lightning, chip, lightning bolt, bar chart, gear). Page 'Home' with a green link icon. Green notice: 'New patch available. Click here to apply.' with a close X. Time 09:12:56. Energy flow diagram with a house in the centre (1.700 kW) and icons for grid (0.000 kW), solar (1.700 kW), battery (green, 0.000 kW and 0.800 kW), a device at left (0.900 kW), electric vehicle and a charger or device at bottom. Label 'Energy manager' at the bottom.
http://reduxi.local. You can find the controller's IP address in your router's device list or in the Reduxi app under Reduxi devices.admin · Password: admin (factory default)Text description of this image
Screenshot of the Reduxi Configurator login page in a Chrome browser window. The address bar shows 'Not secure' and 'reduxi.local'; the address bar is marked with a cyan box and an enlarged copy of it (cyan box, text 'Not secure reduxi.local') is shown at the left, connected by a cyan line. Page background: light grey line drawing of a house with solar panels (green), a wall box, an inverter, a car and a charger. Top left: 'reduxi configurator' logo. Login box in the centre with title 'Login', a language selector (English flag, 'English'), a username field and a password field, and a dark 'Login' button.
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Screenshot of the Reduxi Configurator web interface after login, light theme. Top left: 'reduxi configurator' logo. Header bar: 'Home' at left, green 'Connected' status at top right. Left sidebar: expanded section 'Devices' with a list of entries, then collapsed sections 'Manager' and 'Configuration' and 'Settings'. Main area: energy flow diagram. House in the centre with ring, value 24.20 kW. Grid icon at top left, 24.20 kW (red dot on its line). Solar icon at top right, value '-'. Left icon (battery or device), 6.700 kW (green dot on its line). Right icons (battery storage and a device), values '-'. EV charger icon at bottom left, 31.00 kW. A further device icon at bottom right. Label 'Energy manager' below the house.
5 Add the heat pump to Reduxi
Use these steps to add a new heat pump or to edit an existing one.
5.1 Basic settings
Log in locally to the Reduxi Configurator on the controller (see Point 4) and click + Add device.
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Screenshot of the left sidebar of the Reduxi Configurator. Top: reduxi logo with the text CONFIGURATOR. Collapsed sections: Devices (plus icon) and Strategies (plus icon). Below, two buttons side by side: Add device (plus icon, marked with a blue highlight box) and Add strategy (plus icon). Below them two entries: Settings and Profile. The area to the right of the sidebar is empty white.
In the first step (basic settings), select the basic parameters of the device:
- Device type:
HVAC - Type:
Reduxi Meter - Name: a name of your choice, for example Stiebel Eltron HP
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Screenshot of the Reduxi Configurator add-device wizard, step 1 of 3. Progress bar with three steps: 1 Basic settings (active, black circle), 2 Communication channel (grey), 3 Advanced settings (grey). Heading: Basic settings. Fields: Device type * : empty dropdown; Type * : empty dropdown; Name * : empty text field. Buttons: Back (bottom left), Next (bottom right, dark).
5.2 Communication settings
The communication channel has three parts.
Part 1: connection between the Reduxi Gateway device and the Reduxi Controller. The fields are populated automatically. Fill them in as shown below.
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Screenshot of the Reduxi Configurator add-device wizard, communication step, partly cropped at the top (step tabs cut off). Heading: Communication channel and device configuration. Fields: Connection *: TCP-IP; IP *: gateway.local; Port *: 502; Modbus unit ID *: 1. The image is cut off below the Modbus unit ID field.
Part 2: current sensor settings of the Reduxi Gateway device. Choose Auto detect from gateway for all current sensors.
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Screenshot of three input rows of the Reduxi Configurator communication channel form, each a dropdown with a small grey caption below it. Row 1: label CT- L1, selected value Auto detect from gateway, caption Current transformer. Row 2: label CT- L2, selected value Auto detect from gateway, caption Current transformer. Row 3: label CT- L3, selected value Auto detect from gateway, caption Current transformer.
Part 3: signals of the relays of the Reduxi Gateway device. The combination of the two relay states sets the SG-ready mode of the heat pump:
| Mode | Meaning | Relay 1 | Relay 2 |
|---|---|---|---|
| ON | Normal operation | NO (open) | NO (open) |
| OFF | No operation | NO (open) | NC (closed) |
| ECO | Slightly increased power operation | NC (closed) | NO (open) |
| BOOST | Increased power operation | NC (closed) | NC (closed) |
NO stands for normally open, NC for normally closed. The pictures show the setting of each mode.
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Screenshot cut from a heat pump manual table (German text, white row, grey line at the top edge). Left cell: a small drawing of a terminal block with numbered terminals 1, 2, 3 and the label X.1.13, with a black line symbol and red vertical lines above the terminals. Middle cell: Automatikbetrieb Normaler Wärmepumpenbetrieb Betriebszustand 2 [Automatic mode, normal heat pump operation, operating state 2]. Right cell: Die Wärmepumpe heizt und kühlt nach den eingestellten Sollwerten und dem Zeitprogramm. [The heat pump heats and cools according to the set setpoints and the time programme.]
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Screenshot cut from a heat pump manual table (German text, grey row). Table header: Eingang, SGI-Betriebszustand, Beschreibung. Left cell: a small drawing of a terminal block with numbered terminals 1, 2, 3 and the label X.1.13, with a black line symbol and red vertical lines above the terminals. Middle cell: Frostschutzbetrieb Wärmepumpe Aus Betriebszustand 1 [Frost protection mode, heat pump off, operating state 1]. Right cell: Puffer /Heizkreis 1 Solltemperatur 5°C Regeldynamik 10 Warmwassersolltemperatur 10°C [Buffer / heating circuit 1 setpoint temperature 5°C, control dynamics 10, hot water setpoint temperature 10°C].
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Screenshot cut from a heat pump manual table (German text, grey row). Left cell: a small drawing of a terminal block with numbered terminals 1, 2, 3 and the label X.1.13 (the top edge shows the end of another label X.1.13). Above the terminals a black line symbol: a vertical line on the left, a horizontal line across the top and a diagonal line at the right that does not touch the terminal, with red vertical lines running down to the terminals. Middle cell text: Erhöhte Sollwerte Erhöhter Wärmepumpenbetrieb Betriebszustand 3 [Increased setpoints, increased heat pump operation, operating state 3]. Right cell text: Raumsolltemperatur für Heizkreis 1, Heizkreis 2 und Heizkreis 3 werden auf Raumsolltemperatur +2K gesetzt. Zeitprogramme werden berücksichtigt! Warmwassersollwert +5K aber maximal 60°C. Ist der Parameter WW-Lernen Aus, ist die Folgeschaltung aktiv! Ist der Parameter WW-Lernen Ein, ist die aktuelle Speichertemperatur bis 0:00 Uhr aktiv. Anschließend greift wieder die 5K Erhöhung. [Room setpoint temperature for heating circuits 1, 2 and 3 is set to room setpoint temperature +2K. Time programmes are taken into account. Hot water setpoint +5K but maximum 60°C. If the parameter WW-Lernen is Off, the sequential circuit is active. If the parameter WW-Lernen is On, the current storage temperature is active until 0:00. Afterwards the 5K increase applies again.]
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Screenshot cut from a heat pump manual table (German text, white row). Left cell: a small drawing of a terminal block with numbered terminals 1, 2, 3 and the label X.1.13. Above the terminals a black line symbol: vertical lines on the left and right joined by a horizontal line across the top (closed), with red vertical lines running down to the terminals. Middle cell text: Maximale Sollwerte Maximaler Wärmepumpenbetrieb Betriebszustand 4 [Maximum setpoints, maximum heat pump operation, operating state 4]. Right cell text: Raumsolltemperatur für Heizkreis 1, Heizkreis 2 und Heizkreis 3 werden auf Raumsolltemperatur +5K gesetzt. Zeitprogramme werden berücksichtigt! Warmwassersollwert +10K aber maximal 60°C. Ist der Parameter WW-Lernen Aus, ist die Folgeschaltung aktiv! Ist der Parameter WWLernen Ein, ist die aktuelle Speichertemperatur bis 0:00 Uhr aktiv. Anschließend greift wieder die 5K Erhöhung. [Room setpoint temperature for heating circuits 1, 2 and 3 is set to room setpoint temperature +5K. Time programmes are taken into account. Hot water setpoint +10K but maximum 60°C. If the parameter WW-Lernen is Off, the sequential circuit is active. If the parameter WW-Lernen is On, the current storage temperature is active until 0:00. Afterwards the 5K increase applies again.] The top edge shows the last line of the row above: Anschließend greift wieder die 5K Erhöhung.
Complete configuration of the relay signals in the Reduxi Configurator:
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Screenshot of the Reduxi Configurator relay signal settings: eight dropdown fields, each with a grey caption. Off - relay 1: Off (caption: Setpoint of the relay 1 when heat pump setpoint is off). Off - relay 2: On (caption: Setpoint of the relay 2 when heat pump setpoint is off). ECO - relay 1: Off (caption: Setpoint of the relay 1 when heat pump setpoint is ECO). ECO - relay 2: Off (caption: Setpoint of the relay 2 when heat pump setpoint is ECO). ON - relay 1: On (caption: Setpoint of the relay 1 when heat pump setpoint is ON). ON - relay 2: Off (caption: Setpoint of the relay 2 when heat pump setpoint is ON). BOOST - relay 1: On (caption: Setpoint of the relay 1 when heat pump setpoint is BOOST). BOOST - relay 2: On (caption: Setpoint of the relay 2 when heat pump setpoint is BOOST).
5.3 Advanced settings
Advanced settings are optional. They depend on the needs of the location where the Reduxi Controller is installed. After you finish them, click Done at the lower right.
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Screenshot of the Reduxi Configurator add-device wizard, step 3 of 3 (Advanced settings). Progress bar with three black circles 1 Basic settings, 2 Communication channel, 3 Advanced settings (active). Heading: Advanced settings. Eight yes/no questions, each with a toggle that is off and a small default hint at the right: Do you want to set data-saving interval? (Default: 1 min); Do you want to set reading delay? (Default: 1000 ms); Do you want to set writing delay? (Default: 1000 ms); Do you want to set power generation limits and capabilities?; Do you want to set power consumption limits and capabilities?; Do you want to limit communication with the device to read-only? (Default: No); Do you want to invert direction for energy import and export? (Default: No); Do you want to exclude device from summary? (last question, small text; Default: No). Bottom row of three dropdowns: L1 is connected to main feed: L1; L2 is connected to main feed: L2; L3 is connected to main feed: L3. Buttons: Back (left) and a dark button at the right (label small, reads Done).
5.4 Test communication
Click Test communication at the lower right, below the communication parameters. It reads the device once and saves nothing. If the test succeeds, click Done: only Done creates the device.
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Screenshot of the bottom button row of a Reduxi Configurator form. Left: button Back. Right: button "Test communication" marked with a blue box, and a dark button Next to its right.
The test returns one of two results:
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Screenshot of a Slovenian-language dialog titled "Test komunikacije" [Communication test] with a close button (x) at top right. Green text: "Successful readout from device". Values: Active power: 28392 W; Current L1: 45.329 A; Current L2: 45.329 A; Current L3: 45.329 A; Import active energy: 0 Wh; Relay 1 state: false; Relay 2 state: false; Voltage L1: 231.0 V; Voltage L2: 232.0 V; Voltage L3: 233.0 V; Additional parameter - POWER_ACTIVE_L1: 9423; Additional parameter - POWER_ACTIVE_L2: 9464; Additional parameter - POWER_ACTIVE_L3: 9505. Button at bottom right: "Zapri" [Close].
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Screenshot of a dialog titled Test communication (close x at the top right). First box: Unable to communicate with device. Second box (red text): Unable to communicate with 192.168.1.206 on port 502. Check if service is enabled on device, port number is correct and device is reachable on the network. PING 192.168.1.206 (192.168.1.206) 56(84) bytes of data. --- 192.168.1.206 ping statistics --- 2 packets transmitted, 0 received, 100% packet loss, time 1062ms. Dark button at the bottom right: Close.
6 Check the readings
6.1 Last measurements
After communication is established, check the values under Devices – Stiebel Eltron HP in the Reduxi Configurator as an additional test.
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Screenshot of the Reduxi device page for a heat pump, Last measurements tab (tabs: Last measurements, Analysis, Archive; a dropdown and refresh icon at top right). Top tiles: "Control type" with buttons Auto (dark) and Manual (highlighted teal, selected); a second tile with a row of four small buttons, one highlighted teal (labels small: Off.). Card "Current": three values 0.55, 0.57, 0.59 (phase labels and units small). Card "Power": three values 0.4, 0.0, 0.4. Card "Energy": one value 78.7. Card "Other": rows with values OFF, MANUAL, OFF, OFF, ON. Card "Settings": Voltage values 246.00, 244.40, 246.30. Each value has a small timestamp.
6.2 Enable control by Reduxi
For advanced heat pump control, integrate the device into the Reduxi strategy. Under Devices – Stiebel Eltron HP in the Reduxi Configurator, set the control type to AUTO. Only then do strategy commands affect the heat pump.
To achieve maximum flexibility and energy cost reduction with dynamic prices and dynamic tariffs, define a strategy as described in Strategies for Reduxi controller.
After you have added the device and checked the values, you can also inspect and control it in the Reduxi application.
✓ Summary
Preparation (Points 1–2): Get the Stiebel Eltron documents. Prepare the Reduxi Controller, the Reduxi Gateway device with 3 current sensors and a laptop or tablet.
Heat pump (Point 3): Wire the NO contacts of both relays to the X1.13 connector. Mount the current sensors on L1, L2 and L3.
Add to Reduxi (Points 4–5): Log in to the Reduxi web interface. Add the device as HVAC, type Reduxi Meter. Set the three parts of the communication channel. Run Test communication, then click Done.
Go live (Point 6): Check the last measurements. Set the control type to AUTO. Define a strategy.
→ Common issues
| Issue | Solution |
|---|---|
| Relay modes do not match the heat pump behaviour | Check the relay wiring on the X1.13 connector (black, brown, white wire) and the relay settings of the ON, OFF, ECO and BOOST modes in Point 5. |
| No power values of the heat pump | Check that each current sensor covers one phase wire (L1, L2, L3) and that all current sensors are set to Auto detect from gateway. |
| Open configurator does not open or stays empty | The tunnel is not active yet. Wait about 30 seconds and check that the controller is online. |
Login with admin is rejected |
The password was changed during installation. Ask the installer. The Reduxi account password does not work here. |
reduxi.local does not load |
Your device is not in the same network as the controller. Use the IP address or the tunnel connection. |
| Communication test fails, device shows offline | Check reachability, IP address / port / unit ID, and that the protocol is enabled on the device. |