How long does each part of a geothermal system last?

Why do the unit and the loop age differently?

The indoor unit contains a compressor, a reversing valve, a heat exchanger, fans or a blower and electronic controls. Moving parts and electronics wear, so regular maintenance and energy-efficient operation matter for the unit. The loop has none of those: it is a sealed circuit of buried polyethylene pipe with a circulating pump that sits inside the house. Plastic in stable, cool ground is not exposed to sun, frost cycling or oxygen in the way a rooftop or outdoor unit is.

That split is why the most useful number is not one lifespan but two. For the broader picture across equipment types, see our guide to heating system lifespans in Canada, and for a more general version of this question read ground-source heat pump lifespan.

How long does the indoor geothermal heat pump unit last?

Industry and government sources commonly quote about 20 to 25 years for the indoor equipment, while the figures an installer gives you will depend on the model. Real life varies. A unit that is serviced, sized properly and not forced to short-cycle may last longer, and one that is oversized, poorly drained or starved of airflow may fail earlier. Compressors and reversing valves are the parts that most often decide the end of life.

Parts that fail sooner than the whole unit, such as a fan motor, control board, thermostat or circulation pump, are normal service items and do not mean the system is at the end of its life. Our guide to geothermal heat pump problems lists the usual suspects.

How long does a ground loop last?

A properly installed closed loop is usually sold on a life of 50 years or more, and a correct installation uses fused pipe joints, tested pressure and grouted boreholes so that the loop outlasts several heat pumps. Warranty lengths for loop pipe vary by manufacturer and installer, and a warranty is not the same as a life expectancy, so ask what the paper says.

When loops do fail, the cause tends to be installation quality, such as a poor joint, damage during backfill, or a hole that was not grouted well, rather than age. The guide to loop repair and replacement explains how leaks are found and how a loop is repaired or replaced.

Long-lived underground infrastructure is the central idea behind the Drake Landing borehole field in Okotoks. Its 144 boreholes were meant to work as a heat store for decades, and the community's performance results show how the ground behaved over its operating years.

What shortens the life of a geothermal system?

• Poor sizing. An oversized unit short-cycles, and an undersized one runs flat out. Both wear the compressor.
• Neglected filters and airflow. Restricted air makes the compressor work harder.
• Loop problems. Low flow, trapped air or fluid that is too cold stress the heat pump.
• No servicing. Small faults such as a refrigerant leak go unnoticed and escalate.
• Water quality in open systems. Mineral scaling and fouling can damage heat exchangers.

Regular checks are the cheapest protection, and the geothermal maintenance guide covers what a service visit should include.

What does lifespan mean when you decide to replace?

When the indoor unit nears the end of its life, you may be replacing only the heat pump and reconnecting it to a loop that is still sound. That is much less than the cost of a whole new system, which is a strong reason the loop is usually treated as long-term infrastructure. Have a technician check loop pressure, flow and entering fluid temperatures before you decide, so you know the loop is healthy and sized for the new unit.

Whether a repair is worth it on an older unit is a judgment call about age, repair history and cost, and the repair or replace decision guide gives a method. Costs depend on region and quotes decide, so ask for the replacement scope in writing.

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