Why is my thermostat timed out?

First, make sure the thermostat is powered on. Then call TCS Technical Support or follow the troubleshooting steps below:

  1. Confirm the thermostat is addressed correctly. It should not have the same address as any other stat or controller on the network nor can it be address 248.
  2. Check the baud rate and make sure it matches the port baud rate, (default is 9.6k).
  3. Check the A/B/Ref wires insuring they are making good contact. You may need to loosen the screws and reconnect the wires. If too many strands of wire are broken, you may need to re-strip the wires.
  4. Unplug the A/B/Ref connector and measure DC voltage (with no terminating resistors).
    1. Measure across pins A to Ref. It should read about .4 vdc
    2. Measure across pins B to Ref. It should read about 4.6 vdc
    3. Then take the same readings on the screw heads of the A/B/Ref plug. As long as there are additional thermostats installed on the network, you should receive the same readings. Note: if this is the only stat on the network, then a regular QD1010USB will give slightly lower readings.
    4. If both readings are correct, plug the A/B/Ref wire back into the stat and go to step 5.
    5. If the readings are not correct on the stat, remove all wires except the power from the thermostat and try the measurement again.
  5. After you’ve confirmed correct measurements, check the wires you unplugged for unwanted voltages or shorts. You can plug them in one at a time and keep checking the A/B/Ref readings. If they go astray again, unplug the last connector you plugged in and trace those wires down to find the problem.
  6. If it is still not reading correctly, call TCS Technical Support for additional troubleshooting steps.