Service & TroubleshootingQuestion 90 of 110
The most likely cause of no cooling when the thermostat calls but the outdoor unit is completely silent is what?
a.Low refrigerant subcooling
b.A dirty air filter
c.A loss of power, a failed contactor, or an open safety/control circuit
d.Excess superheat
Explanation
A silent outdoor unit on a cooling call usually points to an electrical issue: tripped breaker, blown fuse, failed contactor, or an open safety such as a float switch or high-pressure switch. The technician traces control voltage and power to isolate the fault. Refrigerant issues usually still allow the unit to run.
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