How much does an AC contactor replacement cost?

Prices checked October 2026. Wages: BLS, May 2025.

The contactor is the switch that turns your outdoor unit on and off. When the thermostat calls for cooling, a low-voltage signal pulls it closed and sends full power to the compressor and fan. When the call ends, it opens. Worn, pitted or burned contacts can keep the unit from starting or make it run in fits. Sometimes they stick shut, and the unit keeps humming along after the house is cool.

AC contactor replacement: typical bill

Low$110

Typical$150

High$330

Part $26 (online list price, middle of 9 listings) plus about 0.75 hours of hands-on time and a trip and diagnosis hour, billed at roughly $70 an hour (a HVAC technician earning the national median of $29 an hour, times the 2.4 billing multiplier we use). Method.

The figure above is one service visit to replace it in a central air conditioner or heat pump outdoor unit. The model adds the online list price of a typical two-pole, 30 to 40 amp contactor with a 24 volt coil to about an hour and three quarters of billed time. Roughly 45 minutes of that is hands-on, and an hour goes to travel and diagnosis. The time is priced from what HVAC technicians earn in your area, marked up to cover what it costs a company to put a truck and a trained person at your door.

What moves the price

Diagnosis and travel

Most of the bill on a small electrical repair is the first hour: driving out, finding the cause and confirming it. A good technician proves the contactor is the culprit before swapping it. The thermostat, the low-voltage wiring, a safety switch and the capacitor sitting right beside it can all mimic a bad contactor.

Part type

Contactors come in single-pole and two-pole versions and several amp ratings, and some brands use their own parts. Manufacturer-branded contactors list for several times more than generic equivalents at the same retailer. Either can be fine if the ratings match.

Bundled repairs

Because the capacitor sits beside the contactor and both wear from heat and cycling, technicians often suggest replacing both on one visit. That can be sensible on an older unit, but it should be your choice and listed as two items.

Regional labor cost

The billed rate in the model is based on the 25th percentile, median and 75th percentile HVAC wages for your metro or state, multiplied by factors that reflect typical contractor overhead and profit. In high-wage metros the labor share dominates even more.

Repair or replace?

Replace a failed contactor whatever the system's age. It is a small part, and the repair restores normal on and off control. Pause only when the contactor burned because of something else, like a compressor pulling too much current or loose high-voltage connections. Ask for the readings if the technician finds that. An outdoor unit near DOE's average life for your region, with a compressor showing signs of failure, is a candidate for planned replacement before the service calls start piling up.

Run the numbers for your unit.

What a complete quote lists

What was tested and why the contactor was identified as the cause
Contactor part number with pole count, amp rating and coil voltage
Labor time or flat repair price
Trip or diagnostic charge, stated separately or as included
Any additional parts recommended, priced separately (capacitor, wire, surge protector)
Confirmation the system was tested in cooling mode after the repair
Parts and labor warranty periods

Paste your quote and we'll tick these off for you.

Common questions

What does a bad contactor sound or look like?

Common signs are a click at the outdoor unit with nothing starting, a unit that starts and stops unpredictably, or one that keeps running after the thermostat is satisfied. A buzzing outdoor unit can also point to the contactor or the capacitor.

My outdoor unit won't shut off. Is that the contactor?

It is one of the most common causes, since contacts can stick closed. Turn the system off at the thermostat. If the outdoor unit keeps running, switch off its breaker once and call for service. Do not open the unit's panel.

Can I swap the contactor myself?

No. The contactor carries line voltage to the compressor and fan, and the capacitor next to it can hold a charge. This is a job for a licensed HVAC technician or electrician.

Why did the technician also replace the capacitor?

They sit side by side and both wear with heat and cycling. Replacing both on an older unit can avoid a second visit. It should still be offered as an option and listed as its own item.

How long does the repair take?

The swap itself is short once the problem is found. The model allows about 45 minutes hands-on plus an hour for travel and diagnosis. Much of that visit is testing before and after, which is how you know nothing else burned up the old contactor. Clearing leaves and debris from around the outdoor unit while you wait is a safe homeowner job.