Viessmann 7134239 Sensor #5 Instruction Manual

1. Product Overview

The Viessmann 7134239 Sensor #5 is a replacement component specifically designed for use with Domestic Hot Water (DHW) systems in Viessmann Vitodens 200 WB2 and WB2A Series Residential Gas Condensing Boilers. This sensor plays a critical role in monitoring and regulating the hot water temperature within the boiler system.

Key Features:

• Designed exclusively for Domestic Hot Water (DHW) applications.
• Compatible with Vitodens 200 WB2 (models 6-24, 8-32, 11-44, 15-60) and Vitodens 200 WB2A (models 6-24, 8-32) Series Residential Gas Condensing Boilers.
• Ensures accurate temperature readings for efficient boiler operation.

Figure 1: Viessmann 7134239 Sensor #5. This image shows the sensor with its black cable coiled, terminating in a silver-colored probe at one end and an orange multi-pin electrical connector at the other.

2. Important Safety Information

WARNING: Installation, adjustments, service, or maintenance of this sensor and related boiler components must be performed by a licensed professional heating contractor. This individual must be qualified and certified to work with hot water boilers to ensure safety and proper operation. Improper installation can lead to serious injury, property damage, or death.

• Always disconnect power to the boiler before attempting any installation or service.
• Follow all local codes and regulations.
• Refer to the main boiler instruction manual for specific wiring diagrams and safety procedures.

3. Installation

This section provides general guidance for the installation of the Viessmann 7134239 Sensor #5. For detailed, model-specific instructions, always consult the official Viessmann Vitodens 200 WB2/WB2A boiler installation manual.

1. Preparation:
   • Ensure the boiler is completely powered off and isolated from the electrical supply.
   • Allow the boiler and water to cool down to a safe temperature.
   • If replacing an existing sensor, carefully note its location and wiring connections.
2. Sensor Placement:
   • The Sensor #5 is typically installed in a designated well or port within the Domestic Hot Water (DHW) section of the boiler.
   • Ensure the sensor probe is fully inserted into its well to achieve accurate temperature readings.
3. Electrical Connection:
   • Connect the sensor's orange electrical connector to the corresponding receptacle on the boiler's control board. Refer to the boiler's wiring diagram for the exact location.
   • Ensure connections are secure and free from damage.
4. Verification:
   • Once installed, visually inspect all connections.
   • Restore power to the boiler and observe its operation. The boiler's control panel should indicate proper sensor detection.

Note: Before ordering replacement parts, it is crucial to verify compatibility. Provide the manufacturer with the 16-digit boiler serial number or the 12-digit ASME/NB serial number to ensure the correct part is selected.

4. Operating Principles

The Viessmann 7134239 Sensor #5 functions as a thermistor, which is a type of resistor whose resistance is strongly dependent on temperature. As the temperature of the Domestic Hot Water (DHW) changes, the sensor's electrical resistance changes accordingly. The boiler's control unit continuously monitors this resistance to determine the current DHW temperature.

Based on the temperature readings from this sensor, the boiler's control system will:

• Initiate or cease the heating process for DHW to maintain the setpoint temperature.
• Adjust burner output to efficiently reach and maintain the desired DHW temperature.
• Trigger safety shutdowns if temperatures exceed safe operating limits.

This sensor operates automatically as part of the boiler's integrated control system and does not require direct user interaction for its function.

5. Maintenance

The Viessmann 7134239 Sensor #5 is designed for reliable operation and typically requires minimal direct maintenance. However, it is part of a larger boiler system that requires regular professional servicing.

• Annual Boiler Service: Ensure your Viessmann boiler, including all its components like this sensor, is inspected and serviced annually by a licensed heating contractor.
• Visual Inspection: During boiler service, the contractor should visually inspect the sensor and its wiring for any signs of wear, corrosion, or damage.
• Cleaning: If the sensor probe is accessible and shows signs of scale buildup, it may be carefully cleaned by a qualified technician according to manufacturer guidelines.
• Replacement: If the sensor is found to be faulty or providing inaccurate readings during diagnostic checks, it should be replaced with an authentic Viessmann part.

Do not attempt to repair a damaged sensor. Always replace it with a new, genuine Viessmann 7134239 Sensor #5.

6. Troubleshooting

If your boiler system is experiencing issues related to Domestic Hot Water (DHW) temperature regulation, the Viessmann 7134239 Sensor #5 may be a contributing factor. Always consult a licensed heating contractor for diagnosis and repair.

Common Symptoms of a Faulty DHW Sensor:

• Inconsistent DHW temperature (too hot or too cold).
• Boiler displaying error codes related to DHW temperature or sensor failure.
• Boiler short-cycling when heating DHW.
• No DHW production despite the boiler operating for central heating.

Troubleshooting Steps (for Qualified Technicians Only):

1. Check Error Codes: Consult the boiler's control panel for any specific error codes that may indicate a sensor issue.
2. Visual Inspection: Inspect the sensor and its wiring for visible damage, loose connections, or corrosion.
3. Resistance Test: A qualified technician can measure the sensor's resistance at various temperatures and compare it against the manufacturer's specifications to determine if it is operating within tolerance.
4. Wiring Continuity: Check the continuity of the sensor's wiring back to the control board.

If the sensor is determined to be faulty, it must be replaced. Do not attempt to bypass or repair a malfunctioning sensor.

7. Specifications

8. Warranty and Support

For information regarding the warranty of your Viessmann 7134239 Sensor #5, please refer to the documentation provided with your original Viessmann boiler or contact Viessmann customer support directly. Warranty terms and conditions may vary.

Customer Support:

If you require technical assistance, have questions about compatibility, or need to order replacement parts, please contact Viessmann customer service or your authorized Viessmann dealer. When contacting support, always have your boiler's 16-digit serial number or 12-digit ASME/NB serial number readily available to ensure accurate assistance.

You can typically find contact information on the official Viessmann website or in your boiler's main instruction manual.