Symptom
Outside AC unit not running?
If the indoor fan is blowing but the outdoor unit isn't running, the house gets moving air without cooling. Common causes are a tripped breaker or disconnect, a failed capacitor or contactor, a stuck fan motor, or a compressor that won't start. Check the breaker once; if the unit hums or clicks without starting, switch the system off and call.
Soon. A unit that hums without starting can overheat its compressor. Switch cooling off at the thermostat and schedule service.
What usually causes this.
These are the common possibilities, not a diagnosis. A page cannot tell which one it is — that takes a technician testing the system.
- Outdoor unit
- Power
- Tripped breaker or pulled disconnect
- The outdoor unit has its own breaker and a disconnect box on the wall beside it. Either can cut power while the indoor unit keeps running.
- Failed capacitor
- The capacitor gives the compressor and fan motor the boost they need to start. When it fails, the unit often hums without starting. It's one of the most common AC repairs.
- Failed contactor
- The contactor is the switch that turns the outdoor unit on when the thermostat calls. Pitted or stuck contacts stop it starting.
- Fan motor failure
- If the compressor runs but the fan doesn't, the unit overheats and shuts down on its safety limit.
- Compressor problem
- Less common, but a compressor that won't start or keeps tripping its overload is a major repair.
What you can safely check.
- Check the breaker for the outdoor unit and reset it once if it has tripped.
- Check that the disconnect switch or pull-out block beside the outdoor unit is fully in place — without opening anything beyond its cover.
- Look and listen from a safe distance: is it humming, clicking, or silent? Is the fan turning? Tell the technician — it helps.
- Clear leaves, grass and plants from around the unit.
Leave these alone
- Poking the fan blades with a stick to get them spinning — a common internet tip, and a good way to get hurt.
- Opening the unit's electrical panel. Capacitors hold a dangerous charge even with the power off.
- Resetting a breaker that trips again.
Call rather than book online if:
- The breaker trips again after one reset
- You smell burning or see smoke from the outdoor unit
- The unit is humming loudly and the house is heating up
What we check when we get there.
In order, and every time — the point of a diagnostic is to find out which cause it is before anything is replaced.
- 01The technician tests the capacitor, contactor, fan motor and compressor rather than swapping parts until one works.
- 02If a part has failed, you'll hear why — for example, a capacitor that failed early can point to heat or voltage problems worth knowing about.
What it is likely to cost.
Capacitors and contactors are among the least expensive AC repairs. A fan motor is mid-range; a compressor is the most expensive and often prompts a repair-or-replace conversation.
Repair or replace?
A failed capacitor or contactor is a repair on almost any system. A failed compressor on a system past about 12 years old is where replacement deserves a real comparison.
Compare repair vs replacement- Diagnostic / service call
- $89
- Capacitor replacement
- From $179
- Contactor replacement
- From $189
- Condenser fan motor
- $449–$799
- Compressor
- $1,799–$3,499
Prices are starting points for standard work in the Savannah area. Final price depends on the system and site, and is confirmed before work begins. Permits and code-required upgrades may be additional.
Questions people ask about this.
- Why is my outside AC unit humming but not turning on?
- Most often a failed capacitor or a seized fan motor. Switch the system off at the thermostat so the compressor doesn't overheat, and have it tested.
- Is it safe to run just the indoor fan?
- Yes. Setting the thermostat fan to On with cooling off will move air without stressing the outdoor unit while you wait for service.
Work out the decision:Repair or Replace?
Further reading:What salt air does to outdoor equipmentHurricane season and your HVAC: before, during and after a storm
The service that fixes it.
Air Conditioning Repair is the work behind this symptom. Its page covers what is involved, how it is quoted and what we stand behind.
Symptoms that sit next to it.
Systems rarely fail in one way only. If one of these is also true, say so when you book — it narrows the diagnosis before anyone arrives.
Air conditioner not cooling, not starting, freezing up, leaking or making noise.
- AC running but not coolingAn air conditioner can run without cooling properly when airflow is restricted, the indoor coil has frozen, a component has failed, or the refrigerant charge is low because of a leak.
- AC won't turn onWhen an air conditioner won't turn on at all, the cause is usually power, the thermostat, a safety switch that has shut the system off (often a full condensate drain), or a failed electrical component such as a capacitor or contactor.
- AC frozen / iced upIce on an air conditioner's copper lines or indoor coil almost always means the coil is getting too cold — usually because airflow across it is restricted, or because the refrigerant charge is low from a leak.
- AC leaking waterAn air conditioner leaking water indoors is usually a blocked condensate drain, an overflowing or cracked drain pan, or a frozen coil melting.
- AC making a noiseA new noise from an air conditioner usually points to a specific part.
Not sure which it is?Describe it to the assistant
Everything else we are called about.
The whole index, in three groups.
HUMIDITY, AIRFLOW & ENERGY BILLS
House feels humid or dampSome rooms too hot or coldPower bill suddenly higher
Get it looked at.
We cover Savannah, the Coastal Empire and the South Carolina Lowcountry. Tell us what the system is doing — you do not need to know the cause. The diagnostic price is given to you before the visit, and the repair price before any work starts.
No heat, or no cooling at all?Call rather than send a request — (912) 858-3737 is answered around the clock.