GROHE 38422000 WC Concealed Cistern 0.82 m Single User Manual

1. Product Overview

The GROHE 38422000 WC Concealed Cistern is designed for wall-mounted toilet installations, offering a compact and efficient solution. This cistern supports both dual and single flush operations and features a low-noise filling valve for quiet performance. It has an installation height of 0.82 meters and allows for front or top actuation. Water supply connection can be made from the left, right, or back. The unit is insulated against condensation and includes an angle stop valve (1/2 inch), flush pipe fixing brackets, and a protecting block. It requires a minimum recommended static pressure of 0.2 bar and is suitable for use with horizontal plates. The water supply connection is 0.5 inches.

Figure 1: Front view of the GROHE 38422000 WC Concealed Cistern.

2. Safety Information

• Read all instructions carefully before installation and use.
• Installation should be performed by a qualified professional in accordance with local plumbing and building codes.
• Ensure the main water supply is turned off before beginning any installation or maintenance work.
• Wear appropriate personal protective equipment (PPE) during installation.
• Do not modify the product in any way, as this may void the warranty and create safety hazards.
• Inspect all components for damage before installation. Do not install damaged parts.

3. Package Contents

The GROHE 38422000 WC Concealed Cistern package includes the following items:

• 1x WC Concealed Cistern unit
• Angle stop valve (1/2 inch)
• Flush pipe fixing brackets
• Protecting block
• Installation hardware (screws, anchors, etc. - implied by "fixing brackets")

4. Specifications

Figure 2: Dimensional drawing of the GROHE 38422000 WC Concealed Cistern (dimensions in mm, G 1/2 for water connection).

5. Installation

This section provides general guidance for installing the GROHE 38422000 WC Concealed Cistern. For detailed, step-by-step instructions, always refer to the specific installation guide provided with your product and consult a qualified plumber.

5.1 Pre-Installation Checks

• Ensure the wall structure is adequate to support the weight of the cistern and a wall-hung toilet when filled with water.
• Verify that the required minimum static pressure of 0.2 bar is available at the water supply point.
• Confirm all necessary tools and additional materials (e.g., wall fixings suitable for your wall type, sealing materials) are on hand.
• Familiarize yourself with the components using the exploded view diagram.

Figure 3: Exploded view of the cistern components, showing parts for assembly and connection.

Figure 4: Perspective view of the GROHE 38422000 WC Concealed Cistern, showing top and side details.

5.2 Mounting the Cistern

1. Position the cistern at the desired installation height (0.82 meters) and mark the drilling points for the flush pipe fixing brackets and the main cistern frame.
2. Drill holes and secure the cistern frame to the wall using appropriate fasteners. Ensure the cistern is level and securely mounted.
3. Install the flush pipe fixing brackets as indicated in the product's specific installation manual.

5.3 Water Supply Connection

1. Connect the 0.5-inch water supply line to the angle stop valve. The connection can be made from the left, right, or back of the cistern.
2. Ensure all connections are watertight using appropriate sealing materials.
3. Slowly turn on the main water supply and check for leaks.

5.4 Flush Pipe and Actuation Installation

1. Connect the flush pipe to the toilet bowl according to the toilet manufacturer's instructions.
2. Install the chosen actuation mechanism (flush plate) for front or top operation. Refer to the actuation plate's specific manual for detailed steps.
3. Ensure the protecting block is correctly positioned to prevent damage during installation of the flush plate.

6. Operation

The GROHE 38422000 WC Concealed Cistern offers both single and dual flush options, depending on the flush plate installed.

6.1 Single Flush Operation

For a single flush, press the designated button on the flush plate. This will release a full volume of water to clear the toilet bowl.

6.2 Dual Flush Operation

If your flush plate supports dual flush, there will be two buttons or a single button with two distinct press areas. Press the smaller button for a reduced flush volume (e.g., for liquid waste) and the larger button for a full flush volume (e.g., for solid waste). This feature helps conserve water.

6.3 Low Noise Filling

The cistern is equipped with a low-noise filling valve, ensuring quiet operation during the refilling process after each flush.

7. Maintenance

Regular maintenance ensures the longevity and optimal performance of your GROHE concealed cistern.

• Cleaning: Clean the flush plate and visible parts with a soft cloth and mild, non-abrasive cleaner. Avoid harsh chemicals that can damage finishes.
• Leak Checks: Periodically check for any signs of water leaks around the cistern or connections. Address any leaks immediately to prevent water damage.
• Internal Inspection: If access to the internal components is required (e.g., for valve inspection or replacement), ensure the water supply to the cistern is turned off first. Consult a qualified plumber for internal maintenance.
• Condensation: The cistern is insulated against condensation. If condensation issues arise, ensure proper ventilation in the installation area.

8. Troubleshooting

This section addresses common issues you might encounter with your concealed cistern. For complex problems, contact a qualified plumber or GROHE customer support.

• Cistern Not Filling:
  • Check if the main water supply valve is open.
  • Ensure the angle stop valve (1/2 inch) connected to the cistern is fully open.
  • Verify that the minimum static pressure of 0.2 bar is met.
• Cistern Fills Continuously / Water Running into Bowl:
  • This usually indicates an issue with the fill valve or flush valve seal.
  • Turn off the water supply to the cistern and consult a plumber for inspection and repair.
• Weak Flush:
  • Check for any obstructions in the flush pipe or toilet bowl.
  • Ensure the water level in the cistern is reaching the correct fill line.
  • Verify that the flush plate mechanism is correctly engaging the flush valve.
• Flush Plate Not Actuating:
  • Ensure the flush plate is correctly installed and aligned.
  • Check for any physical obstructions preventing the buttons from moving freely.

9. Warranty and Support

9.1 Product Warranty

GROHE provides a 5-year guarantee for this WC Concealed Cistern. This warranty covers manufacturing defects under normal use and service. Please retain your proof of purchase for warranty claims. For full terms and conditions of the warranty, please refer to the official GROHE warranty documentation or contact GROHE customer service.

9.2 Customer Support

For technical assistance, spare parts, or warranty inquiries, please contact GROHE customer support. You can find contact information on the official GROHE website or by visiting the GROHE Store on Amazon.