Field Guide · JHC Services
AC Running But Not Cooling? Here's What It Usually Is
The four most common causes when a central AC runs without cooling — what you can check yourself and when to shut it off and call.
Check these two things first
Before calling anyone: check the filter and check the outdoor unit. A suffocating filter can freeze the indoor coil and stop cooling entirely — if the filter looks like felt, replace it, shut the system off for a few hours to thaw, and try again. Outside, confirm the fan on the condenser is actually spinning when the system calls for cooling.
The usual suspects
If the outdoor unit hums but the fan won't start, that's the classic failed capacitor — one of the cheapest repairs in HVAC when caught early, and one of the most expensive when the compressor overheats trying to start against it.
If everything runs but the air is barely cool, the system is likely low on refrigerant from a leak, or the outdoor coil is matted with dirt and cottonwood. Refrigerant doesn't get used up — low charge always means a leak, and a proper repair finds it rather than topping off annually.
Ice anywhere on the refrigerant lines or coil means shut it down. Running an iced system can slug liquid refrigerant into the compressor, converting a service call into a replacement quote.
What a real diagnosis looks like
Pressures alone can't diagnose an AC — they move with the weather. A technician who measures superheat and subcooling can tell you the actual state of the charge and the metering; one who reads a gauge and reaches for the refrigerant jug is guessing at your expense.
Need this handled instead of explained? See our Air Conditioner Repair service — available in Sanders, KY, Hanover, IN, Vevay, IN and across our whole service area.
Rather just have it fixed?
Call or text 812-493-3011 — honest diagnosis, flat pricing, and the same straight talk as the guide.