Your AC isn’t cooling. It’s hot in the house. Your first instinct is to grab the phone and call for service.
Before you do, take ten minutes and walk through this list. About a third of the “my AC isn’t working” calls we get in Buffalo and Niagara Falls turn out to be something the homeowner could’ve handled themselves. A tripped breaker. A clogged filter. A thermostat set wrong. Here’s the list we walk through ourselves when someone describes a cooling problem over the phone.
A few ground rules before you poke around your AC system.
If you see scorch marks, smell burning plastic, or hear your breaker tripping repeatedly, stop. Shut the system off at the thermostat and call a technician. These are signs of electrical problems that can cause fires, and the right move is professional diagnosis, not DIY troubleshooting.
Same goes for refrigerant leaks. If you suspect one (signs include hissing near the indoor coil, ice on refrigerant lines, or a chemical smell), handling refrigerant requires EPA certification and specialized equipment. It’s not something a homeowner can legally or safely deal with.
For everything else on this list, you’re working with controls, filters, breakers, and obvious physical obstructions. Those are fair game.
Start here. It sounds ridiculous, but this is the single most common cause of “my AC isn’t working.” Make sure the thermostat is:
Set to “Cool,” not “Heat,” “Off,” or “Fan Only.” Set below the current room temperature, ideally at least 3 to 5 degrees lower. Fan on “Auto.” “On” runs the fan constantly without cooling, which can feel like broken AC. Actually powered. If the screen is dead, the batteries may need replacing, or a breaker may have tripped.
Programmable and smart thermostats occasionally get their schedules scrambled after power outages or software updates. If the screen shows something weird, check the schedule, or reset to a simple manual mode to see if that gets things running.
A clogged filter is the second most common cause of AC problems in WNY homes. When airflow is restricted enough, the system can literally freeze up the indoor coil, which stops cooling entirely.
Pull the filter out. If you can’t see light through it, it’s too dirty. Replace it with a new one of the correct size (the dimensions are printed on the old frame).
If the coil has iced over from running with a clogged filter, you may need to shut the AC off for a few hours to let the ice melt before it’ll run properly again. Running the fan only will help thaw it out.
AC systems have two circuit breakers: one for the indoor unit (air handler or furnace) and one for the outdoor unit (condenser). If either is tripped, the system won’t cool.
Head to your electrical panel. Look for any breaker that’s sitting halfway between “On” and “Off,” or clearly flipped to “Off.” AC breakers are typically labeled “AC,” “Condenser,” “Air Handler,” or similar.
To reset a tripped breaker, push it firmly all the way to “Off,” then flip it back to “On.” If it trips again immediately or after a short time, stop flipping it and call for service. A breaker that trips repeatedly is telling you something is wrong electrically, and continuing to reset it can cause damage or create a fire risk.
Walk outside and look at your condenser, the big square box usually sitting on a concrete pad next to the house.
A few things to check:
The fan on top of the outdoor unit should be turning when the AC is calling for cooling. If you hear a hum but don’t see the fan spinning, that usually means a failed capacitor or a seized motor. Both require a technician.
Leaves, grass clippings, cottonwood fluff, and dead vegetation can pile up against the coil and block airflow. The system needs to breathe. Clear any obvious debris and make sure there’s at least two feet of clearance around all sides.
If the fins on the outdoor coil are packed with grass clippings or look filthy, that’ll hurt performance significantly. You can gently spray the coil down with a garden hose (from the inside out if possible, but from outside if that’s all you can do). Skip the pressure washer, it’ll bend the fins.
If there’s visible ice on the refrigerant lines (the copper pipes coming out of the unit), shut the AC off and let it thaw for several hours before running it again. Ice typically means low refrigerant, a clogged filter, or an airflow problem, all of which need professional attention.
Head to your furnace or air handler (usually in the basement, attic, or utility closet). A few things to look for:
Your AC produces condensation as it removes humidity from the air. That water is supposed to drain out through a line that typically runs to a floor drain, utility sink, or outside. If that line clogs, water backs up and pools around the indoor unit.
Some systems have a safety switch that shuts the AC off when the drain pan fills, specifically to prevent water damage. If your AC stops working and you find water around the unit, a clogged drain line is the likely culprit.
You can sometimes clear minor clogs by pouring a cup of distilled white vinegar into the drain line access port. If that doesn’t work or you can’t find the access point, that’s a job for a technician.
Same deal as outside: ice means something’s wrong. Shut the system off, let it thaw, and call for service.
Walk through the house. Every supply register (where cold air comes out) should be open and unobstructed. Same for return vents (where air gets pulled back into the system).
Common problems we see: a piece of furniture blocking a return vent, a rug covering a floor register, registers closed during winter that never got reopened, and drapes or curtains blocking airflow.
Blocked returns are especially problematic because they starve the system of air. The blower has to work harder, efficiency drops, and some rooms end up cold while others stay warm.
Newer installations often include a condensate overflow switch, a small device that trips when the drain pan fills with water. When it trips, it shuts the AC down to prevent water damage.
If you’ve checked everything else and the system still won’t run, look for a small float switch near the indoor unit’s drain pan. If the float is stuck up, it thinks the pan is full. Gently try to reset it, but if water keeps backing up, you have a drain line problem that needs a tech.
If you’ve worked through this list and the AC still isn’t cooling, you’re looking at one of a few possibilities that need a professional:
Low refrigerant. Usually caused by a leak, and requires EPA-certified handling. Failed capacitor. The most common electrical failure on AC systems. Bad contactor or control board. Electrical components that wear out over time. Failed compressor. The most expensive failure and often a replace-the-system moment. Frozen coil from airflow or refrigerant issues. Requires diagnosis to find the root cause.
Pricing varies by region, equipment, and the specific problem, but ballpark ranges for common AC repairs in the Buffalo/Niagara Falls area look something like this:
Capacitor replacement: $150 to $350. Contactor replacement: $150 to $400. Refrigerant recharge (not including leak repair): $300 to $700+ depending on refrigerant type and amount. Condensate drain line clearing: $100 to $250. Blower motor replacement: $400 to $900. Evaporator coil replacement: $1,000 to $2,500. Compressor replacement: $1,500 to $4,000+ (often a replace-the-system moment).
Emergency pricing during peak season or after hours runs higher. This is why scheduled maintenance is so much cheaper than reactive repairs.
At that point, get in touch and we’ll send someone out. Our technicians carry most common parts on the truck, and we can usually diagnose and resolve issues in a single visit.
The vast majority of mid-summer AC failures can be prevented with a spring tune-up. That’s not a sales pitch, it’s just the data. A technician catches weak capacitors, low refrigerant, dirty coils, and airflow issues before they become emergencies. Our Paradise Protection Plan automates this, includes priority service, and waives diagnostic fees when something does come up.
For the full picture on what WNY AC systems actually need, see our Homeowner’s Guide to Air Conditioning.
The most common causes are a dirty filter, a frozen coil (usually from restricted airflow or low refrigerant), or a thermostat set incorrectly. Check the filter and thermostat first. If the coil is frozen, shut the system off and let it thaw before running it again.
A repeatedly tripping breaker is a serious sign. It could mean a failing compressor drawing too much current, a short circuit, loose wiring, or an overloaded circuit. Don’t keep resetting it. Shut the system off at the thermostat and call a technician.
No. Running with a frozen coil can damage the compressor, which is the most expensive component in the system. Shut the AC off, set the thermostat to “Fan Only” or just turn the unit off entirely, and let the ice melt completely before running again. If it freezes again, you have an underlying problem that needs diagnosis.
On a hot day, a properly sized system should run in cycles of 20 to 40 minutes. Very short cycles under 10 minutes often mean an oversized system or a thermostat problem. Constant running that never reaches the setpoint usually means an undersized system, low refrigerant, or another issue.
That’s almost always a failed capacitor. The capacitor provides the electrical jolt needed to start the fan motor. When it fails, the motor tries to start but can’t. Shut the system off to prevent damage and call for service. A capacitor replacement is a relatively quick fix.
A small amount of condensation draining outside is normal. Water pooling inside your home near the indoor unit is not. That usually means a clogged condensate drain line, which can cause real water damage if left alone.
Signs include weak cooling, ice on the refrigerant lines, a hissing sound near the indoor coil, and higher-than-usual energy bills. Low refrigerant almost always means a leak, which has to be repaired properly. Adding refrigerant without fixing the leak is a short-term bandage.
If you’ve worked through the list and your AC still isn’t cooling, we can help. Contact Tropical Heating & Cooling or call (716) 870-0753. We’ve been helping Buffalo and Niagara Falls homeowners stay comfortable since 2013, and we’ll get you back up and running as fast as we can.
