Why would an AC that worked fine all summer suddenly quit during a heat wave?
Peak heat is when a marginal component is most likely to fail, since the system is running at its hardest and longest during that stretch — a weakening capacitor or a borderline refrigerant charge that was masked during milder weather often gives out during the season's hottest days.
Is a higher SEER rating always worth it?
SEER (Seasonal Energy Efficiency Ratio) measures cooling output over a typical season divided by the energy used to produce it — higher means more efficient. Whether the jump to a higher-SEER unit pays off depends on local electricity rates and how many hours a year the system actually runs.
Why does the AC keep switching on and off instead of running a full cycle?
Common causes are a dirty air filter restricting airflow, a low refrigerant charge, a failing thermostat sensor, or — on newer installs — an oversized system that satisfies the thermostat too fast. Short-cycling wears the compressor faster than normal operation.
Will a failed capacitor keep the whole system from turning on?
Yes. The capacitor delivers the initial jolt that starts the compressor and fan motors; without it, the system may not start at all, or may start and immediately trip off.
What does a burning smell from the vents usually mean?
Turn the system off first. A burning smell is often an electrical issue — an overheating motor or wiring — rather than anything mechanical, and running it further risks a bigger failure or a safety hazard.
Is it safe to run the AC with ice on the coil?
No — running it iced up restricts airflow further and can push liquid refrigerant back into the compressor, which risks real damage. Turn the system off, leave the fan running if possible to help it thaw, and call.
Why does the outdoor unit need clearance around it?
The outdoor unit needs open airflow to reject heat efficiently — plants, mulch, fencing, or stored items crowding it restrict that airflow, which makes the system work harder and can contribute to compressor strain over time.
Why does the indoor coil freeze up even when it's not that hot outside?
Yes — freezing is usually about airflow or refrigerant, not outdoor temperature. A dirty filter, closed vents, a failing blower motor, or low refrigerant can all starve the coil of the airflow or pressure it needs, and it can ice over on a 70-degree day as easily as a 95-degree one.
Does humidity affect how well an AC cools?
Air conditioners remove both heat and humidity, and pulling moisture out of the air takes part of the system's capacity — on a humid day the same equipment is doing more total work per degree of cooling, so it runs longer even at the same outdoor temperature.
Is Freon still used in new air conditioners?
'Freon' is a old brand name commonly used for refrigerant generally; most systems made after 2010 use a different refrigerant blend due to a phase-out of the original R-22 formulation. Either way, a system 'low' on refrigerant has a leak somewhere — refrigerant isn't consumed during normal operation.
Why does the AC run constantly without actually cooling the house?
This usually points to the system being undersized for the space, a significant refrigerant loss, or a duct problem losing cooled air before it reaches the rooms — all of which need a technician on site to tell apart.
Why does the breaker trip every time the AC starts?
Startup draws the most current a system pulls, so a marginal breaker, a failing start capacitor, or a compressor with a developing short will often only trip at that moment. Repeated tripping shouldn't be reset over and over — call.
Why does the outdoor fan hum but not spin?
Usually a failing run capacitor — it stores the charge that kicks the fan motor and compressor into motion, and when it weakens the motor just hums against the load instead of turning. It's a same-day, inexpensive part on its own, but running the system in that state can stress the compressor.
Is there a temperature too cold to run an air conditioner?
Most residential AC units aren't rated to run reliably below roughly 60°F outdoors — the oil that lubricates the compressor doesn't return properly at low ambient temperatures, which can cause compressor damage over time.
Does turning the AC off and back on use more energy than leaving it running?
For most homes, a moderate setback (a few degrees warmer while away, not fully off) balances savings against recovery time reasonably well. Turning it off entirely on a very hot day can mean a long, hard-running catch-up period later, though it rarely damages a correctly functioning system to do so occasionally.
What's a normal filter-change schedule for central air?
Every 1 to 3 months during the cooling season for a standard filter, more often with pets or high dust. A clogged filter is one of the most common — and cheapest to prevent — causes of an AC service call.
What causes a leak near the air handler?
Almost always a clogged condensate drain line or a cracked drain pan — normal condensation has nowhere to go and backs up. It's not usually an emergency, but it can damage flooring or drywall the longer it sits.
The AC runs but doesn't cool — why?
Several things can cause this independently: low refrigerant from a leak, a failed compressor, a frozen evaporator coil restricting airflow, or a bad capacitor keeping the compressor from actually running. All of them need a contractor's diagnostic to tell apart.
Does the size of the ductwork matter as much as the size of the AC unit?
Yes — a correctly sized AC connected to undersized or leaky ductwork still won't deliver full airflow to every room, which can look like a capacity problem when it's actually a distribution problem. Both matter, and a contractor sizing a replacement should be looking at both.
What's the difference between a refrigerant leak and a low charge from installation?
A system is charged once at installation and shouldn't lose refrigerant over time on its own — if it's low, refrigerant is leaking out somewhere, and topping it off without finding the leak just means doing it again later.
Is upgrading the thermostat worth it for an existing AC system?
It can — scheduling setpoints around when the home is actually occupied reduces unnecessary runtime, though the effect depends on the household's schedule. It doesn't fix an underlying mechanical problem like low refrigerant or a failing capacitor; it only changes when and how often the system is asked to run.