The indoor unit of a geothermal system is expected to last 20 to 25 years. The buried ground loop is expected to last 50 years or more.
A geothermal (ground-source) heat pump has two very different parts. The ground loop is plastic pipe buried in the yard or down boreholes; it has no moving parts and the U.S. Department of Energy puts its life at more than 50 years. The indoor unit holds the compressor, pump and controls, and it lives indoors at a steady temperature with no weather, no debris and no defrost cycles. The DOE estimates up to 24 years for that part.
Because the compressor never sees an outdoor winter, geothermal units outlast air-source heat pumps by a wide margin. When the indoor unit does wear out, it is replaced on its own and the loop stays in service.
Loop pumps, the desuperheater (if fitted) and control boards are the mid-life repairs.
Find the serial number and decode it: Bosch (heat pumps and geothermal) · ClimateMaster · WaterFurnace
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