To connect a room sensor to the s40 thermostat, you need to create a bluetooth low energy (ble) network. this process usually requires an hvac contractor to add at least one smart room sensor to the network. once the first sensor is added by the contractor, you will be able to add as many sensors as you like on your own. if you are still having trouble, please contact lennox technical support at 1-800-453-6669 for further assistance.
For more information or a visual representation of steps please reference our user guide here
