1. Introduction
This manual provides essential instructions for the installation, operation, and maintenance of your Nordyne 903994 Thermostat. This wall-mounted thermostat is specifically designed for heat-only applications with E4EB/E6EB series furnaces. Please read this manual thoroughly before proceeding with installation or operation to ensure safe and efficient use.
For additional information or support, please refer to the contact details provided in the Warranty and Support section.
2. Safety Information
WARNING: Electrical Shock Hazard
- Always disconnect power to the heating system at the main fuse or circuit breaker panel before installing or servicing the thermostat. Failure to do so can result in electrical shock, property damage, or death.
- Installation should only be performed by a qualified technician or licensed electrician in accordance with all local and national electrical codes.
- Do not use this thermostat for applications other than those specified (heat-only, E4EB/E6EB series furnaces).
- Keep the thermostat dry and away from moisture.
3. Package Contents
Verify that all components are present before beginning installation:
- Nordyne 903994 Wall Thermostat (White)
- Mounting Hardware (screws, wall anchors)
- Instruction Manual (this document)

Image 1: Nordyne 903994 Thermostat. This image shows the front of the white, rectangular thermostat, likely featuring a simple temperature control dial or slider.
4. Setup and Installation
This thermostat is designed for quick and simple installation. However, due to electrical connections, professional installation is recommended.
4.1 Pre-Installation Checklist
- Ensure the thermostat is compatible with your heating system (E4EB/E6EB series furnaces, heat-only).
- Gather necessary tools: screwdriver, wire strippers, drill (if new mounting holes are needed).
- Turn off power to the heating system at the main circuit breaker.
4.2 Mounting Location
Select a location on an interior wall, approximately 5 feet (1.5 meters) above the floor. Avoid locations near:
- Drafts from windows, doors, or vents.
- Heat sources such as lamps, sunlight, fireplaces, or appliances.
- Concealed pipes or chimneys.
4.3 Wiring Instructions
- Disconnect Power: Ensure power to the furnace is OFF at the main circuit breaker.
- Remove Old Thermostat: Carefully remove the cover of your old thermostat. Note the wire connections. Take a picture for reference if possible.
- Label Wires: Label each wire with the terminal designation it was connected to on the old thermostat (e.g., R, W, G, Y).
- Remove Old Mounting Plate: Unscrew and remove the old thermostat's mounting plate.
- Mount New Thermostat Base: Thread the wires through the opening in the new Nordyne 903994 thermostat base. Secure the base to the wall using the provided mounting screws and anchors.
- Connect Wires: Connect the labeled wires to the corresponding terminals on the Nordyne 903994 thermostat. This thermostat is designed for heat-only systems. Typically, this involves connecting the R (power) and W (heat call) wires. Refer to your furnace's wiring diagram for specific connections if unsure.
- Attach Thermostat Cover: Once wiring is complete and secure, carefully attach the thermostat cover to the base.
- Restore Power: Turn power back ON at the main circuit breaker.
Note: This thermostat is designed for 230 Volts. Verify your system's voltage requirements before connecting.
5. Operating Instructions
The Nordyne 903994 Thermostat provides simple, manual control for heat-only systems.
5.1 Setting the Temperature
- Locate the temperature control dial or slider on the front of the thermostat.
- Rotate the dial or move the slider to your desired temperature setting.
- When the room temperature falls below the set temperature, the thermostat will activate the heating system.
- When the room temperature reaches the set temperature, the thermostat will turn off the heating system.
This thermostat does not feature a backlight or advanced programming options, offering straightforward temperature management.
6. Maintenance
Your Nordyne 903994 Thermostat requires minimal maintenance to ensure optimal performance.
- Cleaning: Periodically wipe the exterior of the thermostat with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Airflow: Ensure that the thermostat's vents (if present) are not obstructed by dust or debris, as this can affect temperature readings.
- Annual Check: It is recommended to have your entire HVAC system, including the thermostat, inspected by a qualified technician annually.
7. Troubleshooting
If you experience issues with your Nordyne 903994 Thermostat, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Heating system does not turn on. |
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| Room temperature does not match thermostat setting. |
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| Thermostat appears unresponsive. |
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If troubleshooting steps do not resolve the issue, contact Nordyne customer support or a qualified HVAC technician.
8. Specifications
| Feature | Detail |
|---|---|
| Brand | Nordyne |
| Model Name | 903994 |
| Color | White |
| Temperature Control Type | Manual |
| Operation Type | Heat Only |
| Compatibility | E4EB/E6EB series furnaces |
| Voltage | 230 Volts |
| Mounting Type | Wall Mount |
| Product Dimensions | 4.33 x 3.54 x 1.81 inches |
| Item Weight | 0.01 ounces |
| Included Components | Intertherm 903994 Wall Thermostat - Heat Only White |
9. Warranty and Support
Nordyne products are manufactured to high-quality standards. For specific warranty information regarding your 903994 Thermostat, please refer to the documentation included with your purchase or visit the official Nordyne website.
For technical assistance, troubleshooting beyond this manual, or to inquire about replacement parts, please contact Nordyne customer support. Contact information can typically be found on the manufacturer's website or on the product packaging.
When contacting support, please have your model number (903994) and purchase date available.





