The various embodiments described herein include methods, devices, and systems for conditioning air and heating water in a vehicle. In one aspect, a method includes: (1) obtaining a desired temperature for an interior of the vehicle; (2) obtaining a desired temperature for water in a water storage tank of the vehicle; (3) determining a current interior temperature; (4) and a current water temperature; (5) if the current water temperature is below the desired water temperature, and if the current interior temperature is below the desired interior temperature, operating a system in a first mode to concurrently heat the water and heat the interior; and (6) if the current water temperature is below the desired water temperature, and if the current interior temperature is above the desired interior temperature, operating the system in a second mode to concurrently heat the water and cool the interior.