The compressor is the heart of any AC or heat pump. It pumps refrigerant through the system at high pressure, enabling the heat-transfer cycle. Most live in the outdoor unit. They’re also the most expensive component to replace.
Compressor types
- Reciprocating — older technology, found in older units
- Scroll — modern standard, quieter, more efficient, more reliable
- Rotary — common in mini-splits
- Inverter / variable-speed — modern premium. Modulates output instead of cycling on/off. Found in high-end heat pumps and AC.
Why compressor failure usually means replacement
Replacing a compressor in a 10+ year old unit typically costs $1,800-$2,800 — within striking distance of a brand-new system that’s far more efficient and qualifies for current rebates. The traditional “5,000 rule” (repair cost × age) applies: if compressor repair × age > 5,000, replacement is usually smarter.
Common compressor failure causes: undercharged refrigerant (caused by leaks left untreated), debris in the lineset, electrical issues (failed capacitor or contactor going unnoticed), and just plain old age.
Related: Refrigerant, Capacitor, Contactor, Variable-Speed (Inverter).
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Right Way Mechanical is a family-owned HVAC contractor serving Wheat Ridge, Arvada, west Denver, and the Colorado foothills.