by Dan Jape of Reliable Heating, Air & Plumbing
Cold weather is right around the corner and you will soon be in need of heat in your home. Furnaces need a complete service and cleaning each year before they are turned on to make sure they are safe and efficient. Many times, a homeowner will make the assumption that just because a furnace ignites, it is safe to operate. This could not be farther from the truth. Modern day furnaces are a very safe appliance and when maintained, can give years of service. But it is important that the series of safety devices and components that make them safe are in good working order. All modern day furnaces are safe if they are maintained properly, but if neglected could cause a problem. Reliable Heating, Air & Plumbing employees 100 plus Nate certified techs to make sure all is in good shape for a long cold winter.
One of the most important items to check and clean is the heat exchanger. A furnace burns gas and heats up a metal box that contains the gas burners and when the box is warm, a fan blows air across the outside of the box and transfer heat to the air stream, which is then distributed to all the rooms of a home. This heat exchanger heats and cools thousands of times a year and this causes expansion and contraction. This can cause metal fatigue and cracks in this burner box which allows carbon monoxide to leak into the air stream. We have long optical scopes that can be inserted into a heat exchanger to check for cracks and fatigue to make sure they are airtight. This is extremely important to be checked every year, as this piece is a very stressed component of the furnace and can fail at any time a furnace is over 10 to 12 years old. It is also very important that any rust and debris that accumulates in the heat exchanger is vacuumed out to allow all the heat generated by the combustion of the gas to be properly transferred to the air stream.
Another very important series of devices that need to be checked are high temperature limit switches which monitor a furnace for an overheated condition. These high limits are crucial in making a furnace safe and they need to be checked and tested each year to make sure they operate correctly. If a fan or blower stops operating on a furnace, the gas will continue to ignite until these limit devices sense the furnace is overheated and shut off the burners and turn the furnace off. These limit switches are directly in the air stream and take a lot of abuse and they fail after a number of years.
Furnaces have a device that moves air and fumes through the heat exchanger and it is often a component that needs service in a modern furnace. This “draft inducer” is in the combustion stream of the furnace and is exposed to the hot, acid laden fumes of the by-products of gas combustion. Some manufactures make the housing of these inducers out of plastic and they become so hot, the plastic housing cracks allowing flue gases to be emitted into the living space of a home. Some early models also used metal housings and fan blades that was not built out of corrosive resistant materials and they rusted out quickly. These units need to checked at the start of every season for proper operation and integrity of the housing. A complete and through inspection on all the controls on a furnace have to checked every year to assure one all is working properly on their gas furnace.
A gas furnace that a builder installs in your home can give you 14 to 18 years of service if they are taken care of properly and serviced regularly. A furnace that a consumer purchases can last 20+ years and provide safe efficient heat if properly maintained. Have your local heating and air contractor check for correct operation and your family should be warm and safe this winter. If you are need of a new furnace, they start out as low as $1495 and can go up to $3500 for a top of the line model.
