1. Introduction
The Benexmart Zigbee Smart Ultrasonic Heat Meter is designed to accurately measure and display heat energy in water-based heat exchange systems. Utilizing advanced ultrasonic technology and precision electronic components, this meter offers high measurement accuracy, low power consumption, and excellent stability. It is suitable for a wide range of applications, including both cooling and heating systems, and is designed to work seamlessly with the Tuya Smart and Smart Life applications via a Tuya Zigbee Hub.
This meter is ideal for individual metering in district heating systems, thermal energy billing for building complexes, and heating/cooling charge collection for central air conditioning systems, promoting fair billing, energy efficiency, and energy conservation.
2. Safety Information
Please read and understand all instructions before installation and operation. Improper installation or use can lead to inaccurate readings or damage to the device and plumbing system. Always ensure the device is installed by qualified personnel if you are unsure about any steps. The device is designed with threshold alarms to proactively report anomalies, contributing to safety protection.
3. Package Contents
- Ultrasonic Heat Meter unit
- Temperature sensors (pre-attached or separate, typically a pair of PT1000)
- Fittings for selected diameter (DN15, DN20, or DN25)
- User Manual (this document)
Note: A Tuya Zigbee Hub is required for smart functionality and is not included in the product package.
4. Specifications
| Parameter | Value |
|---|---|
| DIY Supplies | Plumbing |
| Work with | Tuya Zigbee Hub (required) |
| Diameter Options | DN15, DN20, DN25 |
| Power | DC3.6V Lithium Battery |
| Accuracy Class | Class 2 |
| Waterproof Rating | IP67 |
| Temperature Range | 5-95℃ |
| Installation | Horizontal or Vertical |
| Pressure Loss | ≤0.02Mpa |
| Connection | Threaded Connection |
| Maximum Working Pressure (MWP) | 1.6Mpa |
| Flow Measuring Range | 1:100 |
| Temperature Sensor | 1.5m standard a pair of PT1000 Temperature Sensor (Length can be customized) |
| Data Storage | Continuous store of 18 months record |
| Power-off Protection | Meter saves records before power-off, recovers measure function after power-back. |
| Communication Protocol | Tuya Zigbee |
| Data Transmission | Each 24h as default |
| Environmental Class | Class A |
| Temperature Difference | (3-90)K |
| Installation Way | Inlet or return water (default is inlet installation) |
| Permanence | Service cycle ≥6 years |
| Display | 8-bit LCD display |
| Anti-magnetic Disturbance | Should not affect water meter measurement and remote disturbance transmission characteristics if intensity of magnetic field interference is not more than 100 ka/m. |
For a visual representation of the product dimensions and components, refer to the diagram below:
Figure 1: Product Dimensions and Components
5. Setup and Installation
5.1 Prerequisites
- A functional Tuya Zigbee Hub is essential for smart features.
- The thermal cycle system must be a mechanically forced circulation system. Natural heat circulation systems may not provide sufficient pressure to meet the heat meter's requirements.
- The heat meter must be installed in a dry, accessible location.
- Professional installation tools are recommended.
5.2 Physical Installation
- The heat meter can be installed in either the inflow pipe or the return flow pipe. The factory default installation is in the inflow pipe. If installation on the return pipe is required, this must be specified before production.
- During installation, ensure the flow direction of the medium matches the arrow indicated on the heat meter's pipe body.
- Regardless of whether the heat meter is installed on the inflow or return flow pipe, the temperature sensors must be connected correctly: the red-labeled sensor for the inflow pipe and the blue-labeled sensor for the return pipe.
Refer to the diagrams below for correct and incorrect installation examples:
Figure 2: Household Heat Meter Installation Picture
Figure 3: Installation Conditions and Notes
5.3 App Pairing (Tuya Smart / Smart Life)
To enable smart features and remote monitoring, pair your Ultrasonic Heat Meter with the Tuya Smart or Smart Life app:
- Ensure your Tuya Zigbee Hub is powered on and connected to your network.
- Open the Tuya Smart or Smart Life app on your smartphone or tablet.
- Navigate to your Tuya Zigbee Hub page within the app.
- Press the "+" button (Add subdevice) to begin searching for new devices.
- On the heat meter, press the physical button to cycle through the display modes until you reach the pairing mode (refer to the operation section for display navigation).
- In the app, click on "LED already blink" or similar prompt to confirm the device is in pairing mode.
- The app will automatically search for and discover the heat meter.
- Once discovered, follow the on-screen prompts to add the device.
A visual guide for app pairing:
Figure 4: Tuya App Device Search
Figure 5: Zigbee Connection Diagram
6. Operation
6.1 Navigating the Device Display
The Ultrasonic Heat Meter features a single physical button for navigating through various display modes. A short press cycles through different parameters, while a long press (5 seconds) may enter configuration or pairing modes.
Watch this video for a demonstration of the physical button operation and display navigation:
Video 1: Ultrasonic Heat Meter Button Operation and App Pairing
The following flowchart illustrates the sequence of display items and button presses:
Figure 6: Display Navigation Flowchart
6.2 Data Display on Meter
The meter's LCD display shows various measurement data. Here's a breakdown of common display items:
Figure 7: Meter Display and Legend
6.3 Heat Quantity Measurement via Tuya App
Once paired, the Tuya Smart app allows you to view comprehensive heat quantity measurement data. This includes total flow, monthly water consumption, and cumulative heat energy. You can also analyze consumption patterns across different time dimensions (daily, monthly, yearly) and receive alerts.
Figure 8: Tuya App Heat Quantity Measurement Interface
7. Threshold Alarms
The heat meter is equipped with a proactive alarm system. When an anomaly occurs, such as an empty pipe, the device reports alarm information. Upon receiving the alert, the Tuya app automatically pushes a notification to users, prompting timely action for safety and system protection.
Figure 9: Threshold Alarm Notification Example
8. User Tips
- **Data Upload Frequency:** The meter does not upload data to the app in real-time. By default, it automatically uploads data to the Tuya app every 24 hours. This setting cannot be changed. Plan your data monitoring accordingly.
- **Zigbee Hub is Key:** Remember that a Tuya Zigbee Hub is absolutely necessary for the smart features of this meter to function. Without it, the meter will operate as a standalone display unit.
- **Installation Direction:** Always double-check the flow direction arrow on the meter body and ensure it aligns with your pipe's water flow. Incorrect installation can lead to inaccurate readings.
9. Maintenance
The Ultrasonic Heat Meter is designed for long-term reliability with a service cycle of ≥6 years and no moving parts in its measurement mechanism, minimizing wear. Regular maintenance is generally minimal:
- **Cleaning:** Periodically wipe the exterior of the meter with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- **Inspection:** Visually inspect the meter and connections for any signs of leaks, damage, or corrosion.
- **Battery:** The meter is powered by a DC3.6V Lithium Battery. If the display becomes dim or unresponsive, the battery may need replacement. Consult the manufacturer or a qualified technician for battery replacement to ensure proper sealing and functionality.
- **Data Storage:** The meter continuously stores 18 months of record data. Ensure regular data backup if critical for your application.
10. Troubleshooting
10.1 Common Issues and Solutions
- No Display/Dim Display:
- Check the battery level. The internal DC3.6V Lithium Battery may need replacement. - Inaccurate Readings:
- Verify correct installation direction (matching the arrow on the meter body).
- Ensure temperature sensors are correctly connected (red for inflow, blue for return).
- Check for air bubbles in the pipe, especially if installed vertically, as this can affect ultrasonic measurement accuracy. - No Data in Tuya App:
- Confirm the Tuya Zigbee Hub is powered on and connected to your network.
- Ensure the heat meter is successfully paired with the Tuya Zigbee Hub.
- Remember that data uploads to the app occur every 24 hours by default, not in real-time. - "Empty Pipe Alarm" Notification:
- This indicates that no water flow is detected in the pipe. Check the water supply and ensure the system is operating correctly. - Difficulty Pairing with App:
- Ensure the meter is in pairing mode (refer to Section 6.1).
- Make sure the Tuya Zigbee Hub is within range and functioning correctly.
- Restart both the meter and the Tuya Zigbee Hub, then try pairing again.
10.2 Anti-magnetic Disturbance
The meter is designed to withstand magnetic field interference up to 100 ka/m without affecting measurement accuracy or remote transmission characteristics. If you suspect magnetic interference beyond this threshold, relocate the meter or consult a specialist.
11. Warranty and Support
For warranty information, technical support, or specific inquiries not covered in this manual, please contact Benexmart Store service directly. Provide your product model and purchase details for efficient assistance.