A temperature control system may include a temperature control device, an electrical wall box having a hole for passing a wire or cable into the wall box, and a gland configured to be inserted into the hole of the wall box. The temperature control device may include a temperature sensor. The wall box may be configured to be mounted to a wall. The temperature control device may be configured to be mounted to the wall box such that the temperature sensor is located within the wall box. A wire or cable may be passed from a wall cavity of the wall, through the gland once inserted into the hole of the wall box, into an interior of the wall box, and attached to the temperature control device. The gland and the wall box may be configured to prevent air within the wall cavity from entering the wall box when the wire or cable is passed into the wall box.