HVAC systems that are over 10 years old are good candidates for replacements according to Energy Star. Swapping an older unit for a new model can lead to greater efficiency and potentially save homeowners up to 20% on heating and cooling costs. Furnaces or boilers that are older than 15 years may also need replacement. However, you’ll need to talk with a contractor or company directly about exactly which services they provide. If you have any queries about exactly where and how to use mouse c...