In Sun City West, near West Whitewood Drive and North Limousine Drive performing Fall preventative maintenance on a Westinghouse furnace. Upon arrival, cycled unit into heating mode. Replaced intake filters and took temperature readings from supply and return. At furnace, cleaned and tightened electrical connections. Took volts and amp draws from components. Checked all safety switches and inspected gas line and flue piping. Vacuumed and wiped down cabinet. Upon departure, unit is working properly and within manufacturer specifications.