The unit's humming, air is moving, but it's warm, and it's the hottest day of the year. Before you pay an emergency trip charge, here's how to tell whether it's a five-minute fix you can do for $0, a cheap part, or the expensive one, and how to keep a repair visit from turning into a same-day sales pitch.
A real share of “no cooling” calls are one of four things you can check yourself: a thermostat setting, a tripped breaker, a clogged filter or iced-over coil, or a blocked outdoor unit. If those are fine, the most common paid fix is a capacitor (cheap part, fair all-in around $150–$300). The two expensive culprits, a refrigerant leak or a failed compressor, are where padding and “you need a whole new system” pitches show up. The rule that protects you: make the technician show you what failed, and keep the repair and any replacement pitch as two separate decisions on two different days.
Honest contractors will tell you a meaningful number of “my AC won't cool” calls end with them flipping a switch you could have flipped yourself. Before anyone's in your living room on the clock, rule these out:
Once the freebies are ruled out, the cause usually falls into one of three buckets, and the price gap between them is enormous. Knowing which one you're in is the difference between a fair $250 and a pressured $8,000.
| Likely cause | Typical all-in | What's going on |
|---|---|---|
| Capacitor / contactor | $150–$300 | A cheap electrical part ($10–$30) that the motors need to start. The bill is mostly the trip, diagnosis, and labor, not the part. The most common and most fixable cause. |
| Low refrigerant (a leak) | varies widely | An AC is a sealed loop. It doesn't burn refrigerant, so “you're low” means it leaked. A “top-off” without finding the leak just buys time. Insist on a leak search. |
| Failed compressor | the big one | The heart of the system. Often the point where “repair” and “replace the whole $5,000–$12,000 system” get blurred together. The case for a second opinion. |
This is the single most-padded answer in cooling repair, so it's worth understanding. Your AC's refrigerant runs in a closed, sealed loop. It does not get “used up” like gas in a car. So if a tech says you're low, the honest translation is: it leaked out somewhere. Paying to “add a pound of refrigerant” every summer means you're paying, year after year, to refill a system that's leaking it right back out.
A straight answer and a willingness to locate the leak is a good sign. A shrug and “eh, they all leak a little, I'll just top it off” is the thing to push back on. (We break the numbers down separately in what a refrigerant recharge should really cost.)
You don't need to know HVAC. You need one habit: “show me, don't just tell me.”
The biggest trap in cooling repair isn't the price of any one part. It's the visit that starts as a $200 fix and becomes “honestly, your system's on its last legs, let me quote you a new one.” That may even be true. But it's a separate decision. Get the cool air back today, then make the replacement call later, calmly, with two or three quotes, not standing in your driveway in 95° heat being told to sign now.
Our free, no-phone-number-required tool walks through your symptoms and your home, then tells you the likely cause, a fair price range, and the exact questions to ask, before anyone's on the clock in your living room.
Walk through it before you call →The real all-in ranges for the common cooling repairs (capacitor, contactor, refrigerant, blower motor, compressor) plus the “show me, don't tell me” questions that keep you from overpaying. One email, no spam.
The most common reasons, cheapest first: the thermostat isn't set to cool below room temperature; a tripped breaker has killed the outdoor unit; a clogged filter has frozen the indoor coil (it can look like ice on the lines); the outdoor unit is blocked by debris; or a cheap electrical part called a capacitor has failed. If the basics check out, a failed capacitor is the most likely paid repair. Low refrigerant and a failed compressor are the less common, more expensive causes.
You can safely do the first-line checks: confirm the thermostat setting, reset a tripped breaker once, replace a dirty filter, thaw a frozen coil by running the fan only, and clear debris from the outdoor unit. Those resolve a real share of calls for $0. Beyond that (electrical parts, refrigerant, or the compressor) is a job for a licensed pro. Don't repeatedly reset a breaker that won't hold, and don't run the system while the coil is iced over.
It depends entirely on the cause. A capacitor, the most common paid fix, runs roughly $150–$300 all-in (trip, diagnosis, and labor; the part itself is only $10–$30). A refrigerant leak varies widely and should always include a leak search, not just a top-off. A failed compressor is the expensive case and is often where a replacement decision enters. Get the compressor's warranty status and a second opinion before committing. These are 2026 ballparks; ask for an itemized number.
No. An AC runs refrigerant in a sealed loop and doesn't consume it, so needing more every year means the system is leaking. Repeated “top-offs” treat the symptom, not the cause. Ask the technician to do a leak search and show you where it's leaking, and to price a permanent repair rather than another refill.
For a cheap part like a capacitor on an otherwise healthy unit, repair, even on an older system. The replacement question only seriously enters with a major failure like the compressor. Either way, treat repair and replacement as two separate decisions: get cooling restored, then compare two or three replacement quotes calmly rather than signing during an emergency visit.