The complexity of the installation, the type of system, and the features of your property all affect how long installing a furnace or heating system takes. A typical installation could take one to three days on average. This involves taking out the old system, setting up the new one, and adjusting it as needed. Customization, extra ductwork, or complicated installations could cause the timetable to grow. To obtain a more precise quote that is customized for your unique circumstances, it is advised that you speak with a qualified installation.