How do I install a relay kit for multiple heater control on my Reznor UBX Unit Heater?

[AndresDella]

Installing a relay kit on your Reznor UBX Unit Heater allows for versatile control, enabling you to manage up to five heaters with a single-stage thermostat or a time clock paired with single or multiple single-stage thermostats. This guide outlines the key steps to ensure a safe and successful installation.

1. Safety First: Begin by completely turning off both the gas and electrical power supplies to the Reznor UBX Unit Heater. This is crucial for preventing accidents.
2. Transformer Replacement (if applicable): If you have a UDX, UDZ, or UEZ model, you'll need to replace the existing transformer. First, carefully mark and disconnect the wires connected to the current transformer. Then, remove the screws securing it. Replace the old transformer with the new one included in the relay kit, and reconnect the wires exactly as they were before.
3. Relay Assembly Installation: Mount the relay assembly. Position the bracket at the rear of the unit. Drill holes if necessary, and secure the assembly and cable clamp using the screws provided in the kit. Be extremely careful to prevent the thermostat leads from coming into contact with any metal surfaces, as this could cause a short.
4. Wiring Connections: Connect the relay to the TEW-type control wiring. Refer to the specific wiring diagram provided with your relay kit for your Reznor UBX Unit Heater model. Strictly adhere to the length and distance specifications outlined in Table 3 of the unit's manual.
5. Wiring Diagram Label: Affix the updated wiring diagram label. Locate the designated spot on the unit. Thoroughly clean the surface before applying the label. Ensure that the label is easily visible and accessible for future reference, marking the appropriate function of your heater.
6. Restore Power and Test: Once all connections are secure, restore both the gas and electrical power to the Reznor UBX Unit Heater. Follow the lighting instructions provided in your unit's manual to ignite the heater. Verify proper operation to confirm that the relay kit installation was successful.