Unit installation

DCN: 141-00885-16 1/26/06 TZ40 Thermostat Manual 29
System Checkout
It is strongly recommended that you hook-up and run a simple bench test before installing the TZ40. Not
only will this save you time in system checkout but will also familiarize you with the thermostat’s
operation.
THERMOSTAT BENCH TEST
1. Connect the Wall Display Unit to the Control Unit with a short (12-24 inch) 4 wire cable.
2. Before power up, set the Control Unit dipswitch, SW1, to ALL OFF
3. Connect power to the Control Unit.
4. Verify Control Unit Status LED is blinking.
5. Verify the WDU display comes on and shows the current temperature.
a. If no display and backlights are not on, check wiring and power at the Control Unit.
b. If a “CF” display is shown on the WDU, double check your wiring to the Control Unit.
d. Do not proceed until the current temperature is displayed on the WDU.
6. With the current temperature displayed on the WDU, we have verified communication between it and
the Control Unit is OK. Any communication problems will result in a “CF” (Communications Failure)
display on the WDU and must be fixed before proceeding. If all is OK with the WDU proceed to the next
step.
7. Press the Fan button on the WDU. The Control Unit’s Fan LED and relay should turn on.
8. Press the Fan button again. The Fan LED and relay should turn off.
9. Press the Mode button until the WDU is showing “H” for Heat Mode.
10. Press the Setpoint Up button until the setpoint is above the current temperature. The Heat LED and
relay should come on. (If they don’t, make sure the Status LED is not flashing twice indicating minimum
off delay…wait until LED stops flashing twice before proceeding).
11. Press the Mode button until the WDU is showing “O” for OFF. The Heat LED and relay will turn OFF.
12. Wait 6 minutes for the minimum off delay to expire. The Status LED will stop flashing twice.
13. Press the Mode button until the WDU is showing “C” for Cool Mode.
14. Press the Setpoint Down button until the setpoint is below the current temperature.
15. The Compressor and Fan LEDs and relays should turn on.
16. Press the mode button until the WDU is showing “O” for OFF Mode.
17. All LEDs and relays should turn off.
18. When you have successfully completed all these tests, you have verified that the TZ40 is working
correctly.