Thank you for contacting us with regards to your model 8346 Thermostat. If the Reset button does not restore normal operation, and if you’ve tried replacing the batteries, something is likely wrong with the thermostat. It may have suffered a static shock that damaged the components on the circuit board. If the unit was installed in 2009, we would recommend that you contact your installer for a replacement model.
Please let us know if you have any further questions.