You probably have a heat exchanger in your home. They are devices used to transfer heat from one form to another or from one fluid to another fluid over a solid surface. Basically, they can help exchange and transfer energy and heat from one item into heat that can be used to warm you up! Heat exchangers are very energy efficient because they can convert energy that may have been wasted into usable heat.
Flame Furnace is offering a secondary heat exchanger inspection for only $49.99! This is a great deal because your heat exchanger needs to checked and/or cleaned periodically in order for it to keep running properly. One thing that can go wrong is fouling-and that is when impurities in the water in the exchanger build up on the exchanger. So contact Flame if you want to get your secondary heat exchanger checked and keep your home nice and warm!
More info on Heat Exchangers: Wikipedia: Heat Exchanger