Major Mechanical Systems Routine maintenance— such as cleaning furnace or air-conditioner filters and scheduling periodic service— might be the only practical way a homeowner can extend the life of major mechanical systems. "Those things go a long way toward making these units last longer," says Gary Kemp, a sales representative at Bell Brothers Heating and Air Conditioning in Des Moines, Iowa. Water quality plays a role in the longevity of boilers, water heaters and water pumps. Water that is highly acidic or full of minerals is tougher on equipment than treated water, and life spans should be lowered accordingly. This is the case in many rural parts of the country, where houses often have their own wells. For heating systems, boilers last longer than hot-air systems because the water helps to moderate heat extremes, making hot and cold cycles less stressful on the equipment. The estimates shown below are for heating and cooling equipment in an adequately insulated house of roughly 2,000 square feet.
|Electric water heater||14||$450-$700|
|Gas water heater||11-13||$650-$1,200|
|Warm-air furnace, heat pump||15||$1,500-$2,500|
|Sources: NAHB 1998 Housing Facts, Figures and Trends; heating and cooling contractors|