A combination of insulation improvements, air sealing, and winterization projects will help ensure your heating system is efficient and long-lasting. The worse your home's insulation, the harder your heating and cooling system will have to work.
This is an extremely important part. If it's not working, you won't receive any heat. Heat exchanger can also be dangerous if they develop any leaks or cracks.
When it comes to furnaces and HVAC systems, the phrase "an ounce of prevention is worth a pound of cure" definitely applies. Manufacturers know this too, which is why they typically void any warranties if regular maintenance is neglected.
The most common type of furnace is a gas-powered central air system, which heats air in a one area and then distributes it throughout the home via ductwork and vents.