1. Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of your Moonshan MS-ZN-20 Instant Hot Water Recirculating Pump. This system is designed to deliver hot water quickly to your faucets, reducing water waste and wait times. Please read this manual thoroughly before installation and use to ensure safe and efficient operation.
2. Safety Information
Important Safety Instructions:
- Read all instructions before installing or operating the pump.
- This recirculating pump is designed for indoor use only with standard tank water heaters. It is not compatible with tankless water heaters.
- Ensure the power supply matches the specifications (110 Volts).
- Installation should be performed by a qualified professional if you are not experienced with plumbing and electrical work.
- Always disconnect power before performing any service or maintenance.
- Do not operate the pump if it has been damaged.
- Keep children and pets away from the installation area.
3. Package Contents
The Moonshan MS-ZN-20 Instant Hot Water Recirculating Pump system includes the following components:
- Recirculating Pump with Timer
- 304 Stainless Steel Sensor Valve
- 20-inch PEX Food Grade Supply Lines (3/8" Comp x 1/2" FIP)
- 1/2" FIP to 3/8" OD Adapters
- Teflon Tape
- Pipe Clamps with Self-Tapping Screws
- Silicone O-Rings
Image 3.1: All components included in the Moonshan Instant Hot Water Recirculating Pump kit. This includes the pump, sensor valve, PEX supply lines, adapters, Teflon tape, pipe clamps, and O-rings.
Image 3.2: Comparison highlighting the 20-inch PEX food-grade supply lines provided with the Moonshan system, emphasizing their longer length and non-toxic material compared to other options.
Image 3.3: Visual comparison of the Moonshan 304 Stainless Steel Sensor Valve with a removable filter screen and a 104°F set temperature, contrasted with a plastic sensor valve from another brand.
4. Setup & Installation
The recirculating pump system is designed for straightforward installation. Follow these steps carefully:
4.1. System Overview
Image 4.1: Diagram illustrating the typical installation of the recirculating pump on the hot water outlet of a tank water heater and the bypass sensor valve under the sink.
The pump is installed on the hot water outlet of your tank water heater. The sensor valve is installed under the sink at the fixture furthest from the water heater. This creates a loop for hot water circulation.
4.2. Installation Steps
- Turn off Water and Power: Locate your water heater and turn off both the main water supply and the power to the water heater.
- Drain Hot Water Line: Open a hot water faucet in your home to relieve pressure and drain some hot water from the lines.
- Install Recirculating Pump:
- Connect the recirculating pump to the hot water outlet of your tank water heater. Ensure all connections are secure and sealed with Teflon tape.
- The pump should be installed in an accessible location.
- Install Sensor Valve:
- At the faucet furthest from the water heater, locate the hot and cold water supply lines under the sink.
- Install the 304 Stainless Steel Sensor Valve between the hot and cold water supply lines using the provided PEX supply lines and adapters. The valve is designed to allow hot water to circulate back to the water heater via the cold water line when the temperature drops below 104°F.
- Ensure the flow direction indicated on the valve (HOT → COLD) is correct.
- Secure Components: Use the provided pipe clamps and self-tapping screws to secure the PEX supply lines and other components as needed, preventing movement and strain.
- Restore Water and Power: Once all connections are secure and checked for leaks, slowly turn on the main water supply. Bleed air from the system by opening hot water faucets until water flows smoothly. Finally, restore power to the water heater and the recirculating pump.
Image 4.2: Diagram illustrating the thermal bypass technology of the one-way sensor valve, showing how hot water is directed to the cold water line for recirculation without affecting the cold water faucet.
Image 4.3: Simplified diagram showing the hot and cold water lines under a sink with the sensor valve installed, indicating the ease of installation.
Video 4.1: An official Moonshan video demonstrating the installation process and features of the Hot Water Recirculating Pump with Timer. This video provides a visual guide to the setup.
5. Operating Instructions
The Moonshan recirculating pump features a programmable timer for efficient operation.
5.1. Timer Control
Image 5.1: Close-up of the programmable timer on the recirculating pump, showing how to set the current time and timer mode for scheduled hot water delivery.
The integrated timer allows you to schedule the pump's operation to align with your hot water usage patterns. This ensures hot water is available when needed, reducing energy consumption during off-peak hours.
- Setting Current Time: Rotate the outer dial to align the current time with the arrow indicator.
- Setting Programmed Cycles: Use the small pins around the dial to set ON/OFF periods. Push pins outwards for ON, inwards for OFF. Each pin typically represents 15 minutes.
5.2. Operating Modes
Image 5.2: Illustration of the three operating modes: Always On, Timer Mode, and Always Off, allowing users to select based on their needs.
The pump typically offers three modes of operation:
- Always On: The pump runs continuously, providing instant hot water at all times. This mode consumes more energy.
- Timer Mode: The pump operates according to the schedule set on the programmable timer. This is the recommended mode for energy efficiency.
- Always Off: The pump remains off. Hot water will only be available after the traditional wait time.
Select the desired mode using the switch or dial on the pump unit.
6. Maintenance
Regular maintenance ensures the longevity and efficient operation of your recirculating pump system.
6.1. Sensor Valve Filter Screen Cleaning
Image 6.1: Diagram showing the replaceable filter screen within the sensor valve, designed to block impurities and prevent clogging.
The 304 Stainless Steel Sensor Valve includes a replaceable filter screen on the hot water port. This screen prevents impurities and particles from entering and clogging the valve.
- Frequency: Inspect and clean the filter screen every 6-12 months, or more frequently if you notice reduced hot water flow or increased noise from the valve.
- Procedure:
- Turn off the water supply to the sensor valve.
- Carefully disconnect the hot water line from the sensor valve.
- Remove the filter screen.
- Rinse the screen under running water to remove any debris. For stubborn deposits, a soft brush may be used.
- Reinsert the clean filter screen and reconnect the hot water line.
- Slowly restore the water supply and check for leaks.
6.2. General Inspection
- Periodically check all connections for leaks.
- Ensure the pump unit is free from dust and debris.
- Listen for unusual noises during operation, which may indicate a problem.
7. Troubleshooting
Refer to the table below for common issues and their solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water or long wait times. |
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| Unusual noise from sensor valve. |
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| Cold water line becomes warm. |
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| Pump not running. |
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Video 7.1: A user-submitted video demonstrating a noisy remote sensor valve. This video highlights a potential issue that may require troubleshooting or replacement of the sensor valve.
8. Specifications
| Feature | Detail |
|---|---|
| Model Number | MS-ZN-20 |
| Brand | Moonshan |
| Material | Stainless Steel (Pump Head, Sensor Valve) |
| Product Dimensions | 7"L x 5"W x 6"H |
| Power Source | Corded Electric |
| Item Weight | 6 Pounds |
| Maximum Flow Rate | 8.4 Gallons Per Minute |
| Maximum Lifting Height | 21.6 Feet |
| Voltage | 110 Volts |
| Wattage | 100 Watts |
| Sensor Valve Set Temperature | 104°F (40°C) |
| PEX Supply Lines Length | 20 inches |
9. Warranty Information
The Moonshan MS-ZN-20 Instant Hot Water Recirculating Pump comes with a one-year warranty from the date of purchase, covering defects in materials and workmanship under normal use. This warranty does not cover damage caused by improper installation, misuse, abuse, accident, or unauthorized repairs.
For warranty claims, please retain your proof of purchase and contact Moonshan customer support.
10. Customer Support
If you have any questions, require technical assistance, or need to report an issue with your Moonshan recirculating pump, please contact our customer support team. Refer to the contact information provided with your product packaging or visit the official Moonshan website for support details.
When contacting support, please have your model number (MS-ZN-20) and purchase date available.
