1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of your Midea 18KW Electric Tankless Water Heater. Please read this manual thoroughly before installation and retain it for future reference. Proper installation and adherence to these instructions are crucial for optimal performance and safety.
2. Important Safety Information
WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, injury, or death. Read these instructions thoroughly before installing or servicing this equipment.
- This appliance must be grounded. To provide continued protection against the risk of electrical shock, connect to a properly grounded circuit that is protected by a recognized CLASS A GROUND-FAULT CIRCUIT INTERRUPTER (GFCI). Installation must be performed by a licensed and qualified electrician.
- All plumbing work must be performed by a qualified plumber in accordance with all local and state plumbing codes.
- Do not operate this water heater if any part has been submerged in water. Immediately contact a qualified service technician to inspect the appliance and replace any part of the control system that has been submerged.
- Ensure the unit is installed in an area protected from freezing temperatures.
- The unit is certified by ETL, NSF, and DOE, and equipped with a 5VA fire-proof cover and durable copper heating elements for safe and reliable operation.
3. Product Overview
The Midea 18KW Electric Tankless Water Heater provides instant and continuous hot water on demand. Its compact design saves space, and intelligent features ensure energy efficiency and user convenience.
3.1 Key Features
- Instant & Endless Hot Water: Powerful 18kW heating system delivers hot water at 130°F or higher without preheating delays.
- Smart Control APP: Manage settings and heating modes remotely via the Smart Home application.
- Convenient Digital Display & Touch Control: Easy temperature setting and clear display of operational status.
- Energy Saving: Self-modulating temperature technology heats water only when needed, potentially saving up to 50% on water heating costs.
- Space Saving: Wall-mounted design occupies significantly less space than traditional tank water heaters.
3.2 Unit Components and Display
The unit features a sleek design with an integrated digital display and touch controls for easy interaction.
4. Installation Instructions
Installation of this electric tankless water heater requires specialized electrical and plumbing knowledge. It is strongly recommended that installation be performed by a licensed electrician and a qualified plumber.
4.1 Pre-installation Checklist
- Verify electrical supply meets the unit's requirements (240 VAC / 60 Hz / Single Phase).
- Ensure adequate circuit breaker capacity (2 x 40 A recommended).
- Confirm minimal wire size (2 x 8 AWG recommended).
- Check water connection type (3/4" NPT).
- Ensure water pressure is within permissible range (30-150 psi).
- Select a suitable wall-mounted location, protected from freezing.
4.2 Mounting the Unit
The unit is designed for wall mounting. Securely fasten the unit to a sturdy wall surface using appropriate hardware.
4.3 Plumbing Connections
Connect the inlet and outlet pipes to the corresponding ports on the bottom of the unit. Ensure all connections are watertight and comply with local plumbing codes.
4.4 Electrical Connections
This step must be performed by a licensed electrician.
Connect the electrical wiring to the unit as per the wiring diagram provided. Ensure a dedicated circuit with the recommended breaker size and wire gauge is used. A Class A GFCI must be installed for protection against electrical shock.
4.5 Initial Startup
After all connections are complete and checked for leaks and proper wiring, slowly open the hot water faucet to allow water to flow through the unit and purge any air from the system. Once water flows steadily, the unit is ready for operation.
5. Operating Instructions
5.1 Power On/Off
The unit will power on automatically when water flow is detected and the main power supply is active. To turn off, ensure no water is flowing and disconnect the main power if extended shutdown is required.
5.2 Temperature Adjustment
Use the touch control panel or the Smart Home app to set your desired water temperature. The digital display will show the current temperature.
5.3 Smart Control App & Wi-Fi Connectivity
The Midea Smart Home app allows for remote control and monitoring of your water heater. Follow the app's instructions to connect your device to your home Wi-Fi network.
- Preset Modes: The app facilitates quick selection of heating modes. Recommended presets include 90°F for washing vegetables/fruits and 104°F for gentle care (e.g., for children).
- Remote Control: Adjust settings and monitor the unit from anywhere, whether it's installed in a bathroom, kitchen, or utility room.
5.4 Automatic Power Modulation
The unit features automatic power modulation, which adjusts the heating power based on the incoming water temperature and desired output temperature. This ensures consistent hot water delivery and optimizes energy consumption.
5.5 Constant Temperature System
The self-adapted heating elements intelligently manage pressure and temperature to provide a stable hot water output, minimizing temperature fluctuations during use.
6. Maintenance
Regular maintenance ensures the longevity and efficient operation of your tankless water heater.
- Cleaning: Periodically wipe the exterior of the unit with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Descaling: In areas with hard water, mineral deposits can accumulate within the heating elements. It is recommended to descale the unit annually or as needed by a qualified technician to maintain efficiency.
- Inspect Connections: Annually check all water and electrical connections for any signs of leaks or corrosion.
7. Troubleshooting
Before contacting customer support, please refer to the following common issues and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water / Unit not turning on | No water flow, power outage, tripped breaker, minimum flow rate not met. | Ensure water is flowing above 0.5 GPM. Check circuit breaker. Verify power supply. |
| Water not hot enough | Temperature setting too low, high flow rate exceeding capacity, cold inlet water temperature. | Increase temperature setting. Reduce water flow. Refer to power capacity guide for your region. |
| Error code on display | Internal fault, sensor issue, overheating. | Refer to the specific error code in the full user manual (if available) or contact customer support. |
| Water flow inconsistent | Mineral buildup, partially closed valve, low water pressure. | Descale the unit. Check all valves are fully open. Verify household water pressure. |
8. Specifications
Detailed technical specifications for the Midea 18KW Electric Tankless Water Heater (Model MHE18W2AWW).
| Specification | Value |
|---|---|
| Product Model | MHE18W2AWW |
| Electrical Supply | 240 VAC / 60 Hz / Single Phase |
| Rated Power Input | 18 kW |
| Max. Amp. Load | 2 x 37.5 A |
| Recommended Minimal Wire Size | 2 x 8 AWG |
| Recommended Circuit Breaker | 2 x 40 A |
| Water Connection | 3/4" NPT |
| Min. Permissible Pressure | 30 psi / 2.07 bar / 0.207 MPa |
| Max. Permissible Pressure | 150 psi / 10.34 bar / 1.034 MPa |
| Min. Water Flow to Activate Unit | 0.5 gpm (1.9 L/min) |
| Width | 11.38" (289mm) |
| Depth | 4.65" (118mm) |
| Height | 15.75" (400mm) |
| Item Weight | 9.48 pounds |
| Maximum Temperature | 140 Degrees Fahrenheit |
| Special Feature | Overheat Protection |
| Installation Method | Wall mounted |
| Included Components | 18kw electric water heater |
| UPC | 840296501771 |
8.1 Power Capacity Guide
The required power capacity depends on your geographical location's inlet water temperature and desired flow rate. Refer to the guide below to determine the appropriate capacity for your needs.
9. Warranty and Support
For warranty information, please refer to the documentation included with your product packaging or visit the official Midea website. For technical support, troubleshooting assistance, or to inquire about service, please contact Midea customer service.
Midea Customer Service: Please refer to your product's warranty card or the Midea official website for current contact information.
