Average Life Expectancies of Systems
Appliances	Life Estimate in Years
Dishwashers	5 to 12
Disposals	5 to 12
Washers and dryers	8 to 12
Water heaters	8 to 12
Refrigerators	15 to 20
Stoves	15 to 20
Microwave ovens	8 to 12
Trash compactors	10 to 14
Gutters and Downspouts	Life Estimate in Years
Galvanized	5 to 20
Copper	Life of home if well-maintained
Heating and Air Conditioning	Life Estimate in Years
Warm air furnace	8 to 12
Heat pumps	8 to 12
Air conditioning compressors	8 to 15
Hot water boilers	30 to 50
Plumbing	Life Estimate in Years
Gas hot water heater	8 to 12
Electric hot water heater	10 to 15
Private disposal systems (septic)	15 to 25
Galvanized water pipes	30 to 50
Roofs	Life Estimate in Years
Selvage or asphalt roll	12 to 20
Wood shake and shingle	15 to 20
Asphalt	15 to 20
Fiberglass	15 to 20
Asbestos shingle	30 to 50
Slate	40 to 75