The most common furnace repairs require that consumers replace cracked heat exchangers, dirty furnace filters, and malfunctioning thermostats. However, most homeowners don’t know when those parts need fixing. Don’t wait too long before making those small repairs on your unit. Regular maintenance and replacement of small furnace components can help cut down expenses and prevent the unit from breaking down altogether. AAA Heating and Cooling recommends the following guidelines for knowing when to fix or replace your furnace: if the unit is over 15-20 years old, it emits strange smells, it makes strange noises, or creates uneven heating. For more information, check out our infographic on furnace repair and replacement.