A useful rule of thumb: if the repair costs more than about a third of a new system's price and the unit is over ten to twelve years old, replacement usually wins — especially if it runs on phased-out R-22 refrigerant or has already needed several repairs. Replacement also lowers your monthly energy bill, since efficiency standards have climbed a lot in the last decade. Repair makes sense when the system is relatively young, the fix is a common low-cost part, and the rest of the unit is healthy. Ask the pro for both numbers — the repair with its remaining life, and the replacement with its efficiency savings — and compare total cost of ownership rather than just each sticker.

A service, or tune-up, is preventive maintenance — cleaning the coils, checking refrigerant levels, testing electrical components, replacing the filter, and catching small problems before they become breakdowns. A repair fixes something that has already failed: a dead capacitor, a leaking coil, a seized motor. Many no-cool emergencies trace back to maintenance that was skipped, so a yearly service is genuinely cheaper than the repair it prevents. When you book, be clear about which you need; if the system is running but inefficient, a service may be enough, but if it has stopped cooling, you need a diagnostic and repair, and the service-call fee is often credited toward the work.

Most common repairs — replacing a capacitor, a contactor, a fan motor, or a thermostat — are finished within the same visit, typically one to two hours once the technician has diagnosed the problem and has the part on the truck. Refrigerant leak repairs take longer because the leak has to be located, sealed, and the system recharged and tested. A compressor replacement or a full system install is a multi-hour to full-day job. If a needed part is not stocked, the diagnosis may happen on the first visit and the repair on a second once the part arrives — ask the tech to confirm parts availability so you know whether it is a one-trip fix.

They can, but adding refrigerant without finding the leak treats the symptom, not the cause. Refrigerant runs in a sealed loop and is not consumed in normal operation — if your system is low, it leaked, and it will leak again. A proper repair locates the leak with dye or an electronic detector, seals it, then recharges to the manufacturer's spec. Simply topping it off buys a few weeks to a season, after which you are paying for another recharge — and on older R-22 systems the refrigerant is expensive enough that repeated top-offs add up fast. If a tech proposes a recharge, ask whether they have found and fixed the leak first.

Some symptoms can wait for a scheduled appointment; others should not. Treat it as urgent if the system has stopped heating or cooling during dangerous temperatures, especially with infants, elderly residents, or anyone with health conditions in the home — that can be a genuine safety issue. A burning smell, repeated breaker trips, or a gas odor near a gas furnace are also urgent and, in the gas case, a call-the-utility situation first. Milder signs — a slightly weak airflow, a higher-than-usual bill, an occasional odd noise — can usually wait for a standard visit at standard rates. When in doubt, describe the symptom to your matched pro and let them help you triage.

A standard service call starts with a diagnostic: the technician inspects the system, tests the electrical components and refrigerant pressures, checks airflow, and identifies the failure. That diagnostic carries a fee, often in the range of seventy-five to two hundred dollars, which many companies credit toward the repair if you proceed. From there the call covers the labor and parts to fix the identified problem. What is usually not included unless stated is work outside the original complaint — replacing additional aging parts, a full system cleaning, or duct work. A clear pro quotes the diagnostic fee up front, tells you whether it is credited, and gives a firm repair price before doing the work.

The best defense is asking to see the evidence. When a technician names a failed part, ask them to show you the reading on their meter or the component itself — a bulged capacitor, a compressor that won't draw, a coil that's leaking. For big-ticket recommendations like a new compressor or a whole system, get a second diagnosis before authorizing; the cost of a second service call is small next to a four-figure mistake. Ask for itemized pricing, confirm whether any parts are under warranty by having them check the model and serial, and be wary of pressure to decide immediately or 'while we're here' add-ons unrelated to your original problem.

Yes, for most HVAC work someone should be home, because the technician needs access to the indoor air handler or furnace, the thermostat, and often the electrical panel, in addition to the outdoor condenser. Being present also lets you approve any change in scope — for example if the diagnosis reveals a second failing part — and to see the evidence a good tech will show you. If you cannot be there, arrange access and a reliable way to reach you by phone for sign-off, and make sure the pro can get to both the indoor and outdoor units. Confirm the access plan with your matched pro when you schedule.