Things You'll Need
The TD322W thermostat controls electrical power to Dimplex heaters. The single-pole thermostat operates either 120 VAC or 240 VAC electrical power rated at 5280 watts. This ensures that the TD322W thermostat is used for controlling most all of the Dimplex heater installations. Check with your model of heater confirming the overall electrical ratings and voltage requirements.
Remove all electrical power from the circuit feeding voltage to the heater unit and thermostat location. Shut off the circuit breaker or remove the fuses.
Strip 3/4 inch from the wire insulation on all wires located inside the thermostat electrical box. Expose the bare copper underneath. There are three wires coming from the main electrical panel. A black wire carries the voltage. The white wire is the neutral and the green wire is the earth grounding wire for a 120 VAC circuit. A 240 VAC circuit will substitute a red wire for the white wire. The red wire also carries voltage from the main electrical panel.
Connect the black wire from the main electrical panel to the screw terminal marked "line" on the rear of the thermostat. Tighten the screw around the wire in a clockwise fashion with the screwdriver.
Secure the black wire from the Dimplex heater to the screw terminal on the thermostat identified as "load."
Attach the green wire from the main electrical panel to the green screw on the thermostat's metal housing. Connect the green wire from the Dimplex heater to the same green screw. Tighten the screw turning it in a clockwise manner.
Touch the white wire, for a 120 VAC circuit, to the remaining wire coming from the Dimplex heater. Twist the two wires together, clockwise, with the wire pliers. For a 240 VAC model, substitute the red wire for the white wire coming from the main electrical panel.
Cover the bare wire connection with a wire nut. Twist the nut into place with a clockwise motion.
Feed the wires into the electrical box. Exercise caution not to pinch wires against the electrical box and the thermostat metal frame. Pull the plastic cover from the thermostat metal frame. Install the vendor-provided screws securing the metal frame to the electrical box. Replace the plastic cover over the thermostat.
Switch on the electrical power to the circuit. Turn the thermostat up to a temperature setting greater than the room. You'll hear a click inside the thermostat to indicate it is on.
Follow all local and national electrical codes whenever installing or servicing any electrical parts.
If you are unsure working with electricity, contact a licensed electrician to perform the work for you.