Outdoor unit dead: check the breaker and the disconnect once
A tripped breaker or a pulled disconnect is a two-minute check. But a breaker that trips again is protecting you from a fault, and Trane's guidance is to call rather than keep resetting it.
What is probably happening
- The outdoor unit's breaker tripped in the panel, often a double breaker labeled AC or condenser.
- The disconnect box on the wall next to the outdoor unit was pulled or switched off, sometimes by a landscaper or roofer.
- A failed contactor or a blown low-voltage fuse on the furnace board, so the outdoor unit never gets the signal to start.
Do this in the next five minutes
- Set the thermostat to OFF.
- In the panel, find the AC breaker. If it sits between ON and OFF, push it fully OFF, then ON. Once only.
- Check the gray disconnect box by the outdoor unit. Make sure the pull-out is seated and any switch is ON.
- Set the thermostat to COOL and wait five minutes. Some units have a start delay.
- If it trips again, leave it off and call. If the breaker was fine and it still does nothing, call.
Do not
- Do not reset a breaker more than once. Repeated trips mean a shorted compressor, a bad motor or a wiring fault.
- Do not open the disconnect box or the unit's electrical panel. It is 240 volts.
- Do not hold the contactor in with a stick. People do. It bypasses the safety controls.
Who to call
A licensed HVAC technician
The contactor, capacitor and control wiring live inside the HVAC unit. If the fault turns out to be in the panel or the feed wire, the HVAC technician will tell you to call an electrician.
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What it should cost
$100 to $250
Service call fee, national range. Labor runs $100 to $250 per hour
Source: Angi, HVAC repair cost, updated August 2026. View source
National published range, not a quote for your job. The full cost table for this trade is on the hvac page.
Ask this contractor, on the phone, before anyone comes out
Tap each one as you ask it.
- Why did the breaker trip? Which part did you measure as the cause?
- Did you check the compressor windings for a short to ground?
- Is the breaker and wire size correct for this unit's nameplate?
- Does the service fee come off the repair?
End the call if
- A compressor replacement quoted without a megohm or winding test shown to you.
- A recommendation to just keep resetting the breaker.