A heating, ventilation, and/or air condition (HVAC) controller assembly to reduce undesired air currents includes a front cover, a back plate configured to be removably secured to the front cover, HVAC controller circuitry, a plurality of wire openings, and an air intrusion barrier configured to extend across the wire openings. The HVAC controller circuitry is configured to be electrically coupled to a plurality of wires extending through a hole in the wall to adjust an environmental characteristic of in a controlled space. Each wire opening is configured to receive only a single wire and each wire is configured to extend through a different one of the wire openings. The air intrusion barrier is configured to receive the wires to generally form a plurality of seals against the wires. The wire openings are configured to substantially support the wires to reduce movement of the wires relative to the air intrusion barrier.