Atwood 91447 Thermostat Assembly Instruction Manual

1. Product Overview

The Atwood 91447 Front Mount ECO and Thermostat Assembly is designed for use with Atwood water heaters. This assembly integrates both the Energy Cut-Off (ECO) and the thermostat into a single unit, ensuring proper temperature regulation and safety cut-off for your water heating system. It is constructed from durable materials to provide reliable performance.

Figure 1: Atwood 91447 Front Mount ECO and Thermostat Assembly. This image displays the black rectangular assembly with two circular thermal sensors. The left sensor is labeled "E.C.O." and the right sensor is labeled "T'STAT". Wiring connections are indicated by "RED" and "BRN" labels. An arrow points upwards with the text "P-T ONLY", indicating a specific orientation or connection point.

2. Compatibility

This thermostat assembly is compatible with the following Atwood electronic (DSI) water heater models:

• G6A-3E, G6A-6E, G6A-7E, G6A-8E
• G10-1E, G10-2E, G10-3E
• GC6A-7E, GC6A-8E
• GC6AA-10E, GC6AA-7E, GC6AA-8E, GC6AA-9E
• GC10A-2E, GC10A-3E, GC10A-4E
• GCH6A-10E, GCH6A-7E, GCH6A-8E, GCH6A-9E
• GCH10A-2E, GCH10A-3E, GCH10A-4E
• GH6-6E, GH6-7E, GH6-8E

Always verify compatibility with your specific water heater model number before installation to ensure proper fit and function.

3. Installation Instructions

Installation of the Atwood 91447 Thermostat Assembly is designed to be straightforward. However, if you are unsure about any step, it is recommended to consult a qualified technician or refer to your water heater's specific service manual.

3.1 Safety Precautions

• Disconnect Power: Before beginning any work, ensure that all power (electrical and propane) to the water heater is completely disconnected.
• Allow Cooling: Allow the water heater to cool down completely before handling components to prevent burns.
• Wear Protective Gear: Use appropriate personal protective equipment, such as gloves and eye protection.

3.2 Required Tools

• Screwdriver (appropriate type for your water heater access panel)
• Multimeter (for testing, optional but recommended)
• Cleaning solution (e.g., acetone or isopropyl alcohol) and clean cloth/scotch-brite pad

3.3 Installation Steps

1. Access the Assembly: Locate and remove the exterior access panel for your Atwood water heater.
2. Identify Existing Assembly: Identify the current ECO and thermostat assembly. Note the wiring connections.
3. Disconnect Wiring: Carefully disconnect the wires from the existing assembly. Pay attention to which wire connects to the ECO and which to the thermostat. The new assembly has labels "RED" and "BRN" for wiring, and "E.C.O." and "T'STAT" for the respective sensors.
4. Remove Old Assembly: Gently pry or unclip the old assembly from its mounting location on the water heater tank.
5. Clean Mounting Surface: It is crucial to clean the surface of the water heater tank where the new assembly will mount. Use a cleaning solution and a clean cloth or scotch-brite pad to remove any dirt, corrosion, or residue. A perfectly flush contact between the assembly and the tank is essential for accurate temperature sensing.
6. Install New Assembly: Position the new Atwood 91447 assembly onto the cleaned surface. Ensure the "P-T ONLY" arrow points in the correct direction as indicated by your water heater's design or the original assembly's orientation. The assembly should sit flush against the tank.
7. Reconnect Wiring: Reconnect the wires to the new assembly. Ensure the correct wires are connected to the ECO and Thermostat terminals as indicated on the assembly.
8. Secure Assembly: Secure the assembly in place. Some models may use clips or a retaining strap.
9. Test Continuity (Optional): Before restoring power, you may use a multimeter to test for continuity across the thermostat and ECO terminals to ensure proper function.
10. Restore Power: Once the assembly is securely installed and wired, restore power to the water heater.
11. Test Operation: Turn on the water heater and verify that it heats water to the desired temperature and cycles off correctly.

Note: Incorrect installation or poor contact with the water heater tank can lead to erratic operation, such as short cycling, failure to heat, or failure to shut off.

4. Operation

The Atwood 91447 Thermostat Assembly operates automatically to maintain the water temperature in your Atwood water heater. The thermostat monitors the water temperature and signals the heating element (electric) or burner (propane) to activate when the temperature drops below the set point, and to deactivate once the desired temperature is reached.

The Energy Cut-Off (ECO) is a safety device designed to prevent overheating. If the water temperature exceeds a safe limit, the ECO will trip, shutting down the heating system to prevent damage or hazardous conditions. If the ECO trips, it typically requires manual resetting or replacement of the assembly after the underlying cause of overheating has been addressed.

This assembly does not feature external controls; temperature adjustments are typically made via the water heater's main control panel, if available, or are fixed by the design of the water heater itself.

5. Maintenance

Regular maintenance helps ensure the longevity and efficient operation of your Atwood water heater and its components, including the thermostat assembly.

• Periodic Inspection: Annually inspect the thermostat assembly and its wiring for any signs of wear, corrosion, or damage.
• Clean Contact Surfaces: Ensure the assembly maintains good, clean contact with the water heater tank. Any buildup of dirt or corrosion can affect temperature sensing accuracy.
• Test Functionality: If you experience inconsistent water temperatures or suspect an issue, you can test the continuity of the thermostat and ECO using a multimeter when the unit is cold and disconnected from power. A faulty thermostat or ECO will show no continuity when it should, or vice-versa.
• Replacement: Thermostats and ECOs can wear out over time. If testing indicates a fault, or if you consistently experience issues like the water heater not heating, overheating, or short cycling, replacement of the assembly may be necessary.

6. Troubleshooting

If your Atwood water heater is not functioning as expected, the thermostat assembly can often be a point of concern. Here are some common issues and troubleshooting steps:

6.1 No Hot Water or Insufficient Hot Water

• Check Power: Ensure the water heater has power (electrical and/or propane).
• ECO Tripped: The ECO may have tripped due to overheating. If tripped, the water heater will not operate. Investigate the cause of overheating before resetting or replacing the ECO.
• Faulty Thermostat: The thermostat may not be signaling the heating system to turn on. Test with a multimeter for continuity.
• Poor Contact: Ensure the thermostat assembly is making firm, clean contact with the water heater tank. A gap or debris can prevent accurate temperature sensing.

6.2 Water Too Hot or Not Shutting Off

• Faulty Thermostat: The thermostat may not be signaling the heating system to turn off when the desired temperature is reached. This can lead to excessively hot water and wasted energy.
• ECO Failure: If the ECO fails to trip when water is dangerously hot, it indicates a critical safety issue. The assembly should be replaced immediately.

6.3 Water Heater Short Cycling or Erratic Operation

• Poor Contact: The most common cause for erratic behavior is poor thermal contact between the thermostat assembly and the water heater tank. Ensure the mounting surface is clean and the assembly is flush.
• Intermittent Fault: The thermostat or ECO may have an intermittent fault. Consider replacement if other troubleshooting steps do not resolve the issue.

For complex issues or if you are uncomfortable performing these checks, contact a certified RV technician.

7. Specifications

Note: This assembly is a thermal switch component for water heaters. Other specifications sometimes associated with "thermostats" (e.g., digital display, touch control, specific voltages like 230V, battery power) typically refer to broader control systems or different types of thermostats, and do not apply to this specific ECO and thermostat assembly.

8. Warranty and Support

For warranty information and technical support regarding your Atwood 91447 Front Mount ECO and Thermostat Assembly, please refer to the documentation provided with your Atwood water heater or contact Atwood customer service directly. Keep your purchase receipt as proof of purchase.

Atwood Customer Service: Please visit the official Atwood website or consult your water heater manual for contact details.