How to connect Kronoterm heat pump with Reduxi Gateway
SG contacts regulate the heat pump via the relay outputs of the Reduxi Gateway. With flexible heat pumps, we can cut electricity costs by 30%.
1 Required equipment and system overview
1.1 Required components
To connect the Reduxi Controller to the Kronoterm heat pump you need:
- Reduxi Controller, connected to the local network (Reduxi Controller)
- Reduxi Gateway with 3x30 current sensors
- AC-DC adapter for the Reduxi Gateway
- UTP cable (LAN) for a wired connection of the Gateway, optional
- Laptop or tablet with internet access to configure the device in Reduxi
The Reduxi Gateway must be added to the Reduxi Controller to commission the heat pump. The connection can be wireless (WLAN) or wired via a UTP cable (LAN). More about the connection: Reduxi Gateway.
The Reduxi Gateway with 3x30 current sensors contains:
- three current sensors, which cover the phase conductors of the heat pump
- two relay outputs, which are physically connected to the SG Ready contacts of the heat pump
1.2 Overview of the connection
The picture shows the entire connection from the 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".
Before you connect the relays, check where the SG contacts are located on the heat pump circuit. The picture shows the SG contacts of a Kronoterm heat pump as an example.
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Photo of a green screw-terminal block on a circuit board. Printed terminal labels from left: A7, GND, A8 (separate block on the left), then D1, D2, D3, D4, D5, D6, D7, D8, 12V (partly cut), GND. Wires are inserted under the screws (white, beige, black, grey, red, one with a yellow sleeve). Two red boxes mark terminal D5 and terminal D8, each with a wire inserted below it.
2 Connect the Reduxi Gateway to the local network
Connect the Reduxi Gateway to your local network first. The Reduxi Controller must already be connected to the same local network (Reduxi Controller).
admin and the password admin.- Wired network: set it up if you connect to the local network with an Ethernet cable.
- Wireless network: set it up if you connect to the local network via Wi‑Fi.
Continue with the next section to connect the relay outputs and install the current sensors.
3 Connect the relays and the current sensors
3.1 Connect the Gateway relays to the SG contacts
Connect the relay outputs of the Reduxi Gateway to the SG contacts as shown in the picture.
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Diagram on a white background combining a product picture and a photo. Left: label "Reduxi Gateway" above a dark grey Reduxi Gateway box with the reduxi logo on top; on its front side are an Ethernet port and two small connectors, plus a power connector at the left end. Right: photo of a green screw-terminal block (terminals with printed labels, including D-numbers and 12V and GND) with white and black wires inserted, label "SG ready contacts" below it. Two lines, one teal and one dark blue, run from the two small connectors on the Gateway to terminals on the block.
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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).
3.2 Install the current sensors
The current sensors measure the electrical power of the heat pump in real time. They are included in the Reduxi Gateway kit. Connect them to the three inputs, one per phase, as shown in the picture.
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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 (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 press the Add device button.
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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, select the basic parameters of the device you want to add:
- Device type:
HVAC - Type:
Reduxi Meter - Name: a name of your choice
The basic settings menu gives three options. Fill in the fields as shown in the picture and name the last field as you like.
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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 two parts. The first part connects to the Reduxi Gateway. Its fields are filled in automatically, as shown in the picture.
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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.
The second part sets the current sensors of the Reduxi Gateway and the heat pump states.
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Screenshot of the lower part of the Reduxi Configurator communication step for a heat pump (top is cut off; a heading, probably about current transformers, is only partly visible). Eight dropdown fields, each with a small hint line "Setpoint of the relay 1 (or 2) when heat pump setpoint is.": OFF - relay 1: Off; OFF - relay 2: On; ECO - relay 1: On; ECO - relay 2: Off; ON - relay 1: value; ON - relay 2: value; BOOST - relay 1: On; BOOST - relay 2: On. Buttons at the bottom: Back (left), Test communication and Next (right).
For all current sensors, select Auto detect from gateway.
Then set the heat pump states OFF, ECO, ON and BOOST. The relay states on the Reduxi Gateway define them. Define 4 different combinations, that is 8 relay settings:
| State | Relay 1 / DI5 | Relay 2 / DI8 |
|---|---|---|
| OFF | ON |
OFF |
| ECO | ON |
OFF |
| ON | OFF |
OFF |
| BOOST | OFF |
ON |
5.3 Test communication
Click Test communication at the lower right, below the communication parameters. It tests the connection to 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 Slovenian-language dialog titled "Test komunikacije" [Communication test] with a close button (x) at top right. First box: "Ni mogoče komunicirati z napravo." [Unable to communicate with the device.] Second box: "Unable to communicate with gateway.local on port 501. Check if service is enabled on device and port number is correct." Then: "PING gateway.local (192.168.1.201) 56(84) bytes of data. 64 bytes from 192.168.1.201 (192.168.1.201): icmp_seq=1 ttl=255 time=0.648 ms. 64 bytes from 192.168.1.201 (192.168.1.201): icmp_seq=2 ttl=255 time=0.747 ms." Then: "--- gateway.local ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1002ms. rtt min/avg/max/mdev = 0.648/0.697/0.747/0.049 ms". Button at bottom right: "Zapri" [Close].
5.4 Advanced settings
The advanced settings are optional and depend on the needs of the location where the Reduxi Controller is installed. When you have finished them, press 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).
6 Check the readings
6.1 Last measurements
After communication is established, check the values on the device as an additional test. On the home screen, open the device selection and choose the new heat pump in the tree structure.
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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 the device to be managed by a strategy, set the management mode to Automatic. In manual mode you can test the different states of 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 inspect and control it via the Reduxi application.
✓ Summary
Preparation (Points 1–2): Collect the Reduxi Controller, the Reduxi Gateway with 3x30 current sensors and the adapter. Connect the Gateway to the local network.
Kronoterm heat pump (Point 3): Connect the two Gateway relays to the SG contacts D5 and D8 (NO contacts). Install the current sensors on phases L1, L2 and L3.
Add to Reduxi (Points 4–5): Log in to the Reduxi web interface. Add the device as HVAC, set the current sensors and the states OFF, ECO, ON and BOOST, then run Test communication.
Go live (Point 6): Check the last measurements and set the management mode to Automatic so that strategies control the heat pump.
→ Common issues
| Issue | Solution |
|---|---|
| The Gateway page does not open | Connect to the wireless network Gateway first. If the popup does not appear, open http://gateway.local in your browser. Log in with admin / admin. |
| Test communication fails | Check that the Reduxi Gateway is powered (first LED from the top glows green) and that it is in the same local network as the Reduxi Controller. Check that the first part of the communication channel is filled in automatically. |
| The heat pump shows no power values | Check that each current sensor covers one phase (L1, L2, L3) and that Auto detect from gateway is selected for all current sensors. |
| The heat pump does not react to the strategy | Set the management mode to Automatic. Check that the relays are connected to the NO contacts: D5 reduces and D8 increases the operation of the heat pump. |
| 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. |