Contactor Repair
A contactor is a controlled switch that supplies power to the outdoor unit when the thermostat calls for cooling. If its contacts are worn or stuck, the unit may not turn on or may remain energized after the call ends. The same behavior can also result from a missing control signal or another wiring fault, so the switch and its command must both be checked.
One symptom.
Several possible causes.
What causes this?
These are possibilities, not a diagnosis. Similar symptoms can come from different parts of the cooling system.
Pitted or burned contact surfaces can prevent a reliable connection to the outdoor equipment.
A stuck contactor can leave outdoor components running after the thermostat stops calling for cooling.
An interrupted low-voltage signal, failed coil, or loose connection may prevent an otherwise functional contactor from closing.
What to look for
Take note of when the problem occurs and what the indoor and outdoor units are doing. Share these clues when you call.
- 01
The indoor unit runs but the outdoor unit does not respond to a cooling call.
- 02
The outdoor unit continues operating after the thermostat has satisfied or been turned off.
- 03
Outdoor operation is intermittent, especially when a cooling cycle starts or ends.
The contactor is in a high-voltage enclosure. If the outdoor unit keeps running unexpectedly, avoid opening it and have a professional address the fault.
What our technician will do
The control circuit and contactor are inspected to confirm why power isn't being switched correctly. The findings help determine which repair, if any, addresses the actual fault. Repair pricing is quoted after diagnosis; review the proposed work and price before approving a repair.
Compare the thermostat's cooling request with the low-voltage signal at the outdoor control circuit.
Safely inspect and test the contactor's coil, contacts, and line/load conditions to distinguish a failed switch from an upstream control problem.
Discuss the confirmed fault and obtain approval before replacing a contactor or correcting associated wiring.
After an approved repair, verify that the outdoor unit starts and stops in response to the cooling call.
What to tell us when you call
- Is your AC blowing warm air or no air?
- Is the outdoor unit running?
- When did the problem start?
- Have you noticed unusual noises, ice, or leaking water?
These details help our technician prepare. You don’t need to diagnose the problem yourself.
Need help with your AC?
Tell us what you've noticed at home. Scheduling depends on your address and the current appointment schedule; contact us to discuss the next step.