AC Not Cooling in a KC Summer? Try This Before You Call

Half the "emergency" AC calls we get in July are issues you can rule out yourself in 10 minutes. Here's the homeowner-safe checklist before you spend money on a service call.

Before you spend on a service call

This list won't fix every AC problem — and on a 100°F July day in Overland Park or Lee's Summit you may still need a tech the same day. But these checks rule out the cheap stuff first.

Step 1 — Check the thermostat

Confirm the thermostat is set to Cool and the fan is set to Auto (not On).
Drop the setpoint 5°F below the current room temperature. If the outdoor unit fires up within a minute or two, the thermostat was either set wrong or had a stale state.
Replace the thermostat batteries if it's a battery-powered unit. Dead batteries are the #1 silent fault.

Step 2 — Check the filter

A clogged filter chokes airflow across the evaporator coil. With no airflow the coil freezes solid — you'll see ice on the copper line outside, and the system blows weak, slightly cool air. Pull the filter. If light won't pass through it, replace it. Then set the thermostat to Off for 1–2 hours to let the ice melt before restarting; otherwise the meltwater can overflow the drain pan.

Step 3 — Check the breaker and disconnect

Look at the breaker panel for a tripped AC breaker. Reset it once. If it trips again, stop — that's a real fault, don't keep resetting it.
Find the outdoor disconnect box on the wall near the outdoor unit. Confirm it's still inserted (some homes have a pull-out style; landscapers and pets occasionally pop them loose).

Step 4 — Look at the outdoor unit

Is the fan spinning? It should be on whenever the system is calling for cooling.
Are the fins clogged with cottonwood fluff, grass clippings, or dirt? Gently rinse the coil from the top down with a garden hose on low pressure — never a pressure washer.
Is the unit buried in vegetation? Trim back to 18–24" of clearance on all sides so it can breathe.

Step 5 — Check the condensate drain

Most KC homes have a float switch in the condensate line that shuts off the AC when the line clogs. A clogged drain near the indoor unit can show up as "the AC won't turn on" or "it just stopped" with no other symptoms. Check for standing water in the drain pan and around the air handler. A wet/dry vac on the drain line outlet (usually a PVC stub outside) often clears a simple clog.

If none of that worked

Now it's likely refrigerant, a failed capacitor, a failed contactor, or a compressor issue — all things that need a licensed technician. Book a same-day diagnostic or, if you've already gotten a repair quote and want a sanity check, we'll review it free.

Bookmark this page — it's worth running through every June before the first 95° day.

Common questions

My AC is blowing air but it isn't cold — what's wrong?

Most common causes: a dirty filter that froze the indoor coil, low refrigerant, or a failed capacitor on the outdoor fan or compressor. Try the filter check + a system rest first. If the line outside the house is frosted or iced, the coil is frozen — turn the AC off and the fan on for 1–2 hours before restarting.

Why does my AC turn on for a few minutes then shut off?

Short-cycling. The most common KC causes are an oversized system (bad sizing at installation), a refrigerant issue, a failing capacitor, or a thermostat that's sensing the wrong temperature. None of these are DIY fixes — they need a tech.

Is it normal for the outdoor AC unit to drip water?

The outdoor unit (condenser) shouldn't drip much in cooling mode — that's normal for a heat pump in defrost mode in winter, but not for AC in summer. The indoor unit, on the other hand, produces a steady stream of condensate that drains away through the condensate line; that's expected.

How often should I change my AC filter in KC?

Every 1–3 months depending on filter thickness, pets, and how much you run the system. KC summers run the AC hard, so a 1-inch filter should be checked monthly during cooling season. A 4-inch media filter typically lasts 6 months.