It's 92°F and humid in Fort Wayne, and your AC is blowing room-temperature air. Before you call for service (and pay $150 just for them to show up), walk through these 8 DIY checks. About 40% of "AC not cooling" calls are fixable by the homeowner in under 30 minutes.
1. Check the Thermostat Settings
- Set to "Cool" mode (not "Heat" or "Off")
- Temperature set at least 3°F below current room temperature
- Fan set to "Auto" (not "On" — "On" blows air continuously even when not cooling, making it feel like it's not working)
- Battery-powered thermostat? Check batteries.
- Smart thermostat? Check app settings and any active schedules that may override manual setting.
2. Replace the Air Filter
A clogged filter is the #1 cause of AC problems in Fort Wayne. Restricted airflow makes the evaporator coil freeze over with ice, which blocks air entirely. You think the AC is broken; it's just iced up because it can't breathe.
Pull the filter. If it's dirty, replace it. Then wait 2-4 hours for any ice on the coil to melt before restarting.
3. Check the Outdoor Unit
Walk to the outdoor AC unit (the condenser). Check:
- Is the unit running? You should hear the fan on top and the compressor humming.
- Are the fins blocked? Tall grass, leaves, cottonwood fluff, or debris around the unit restricts airflow.
- Are the fins bent? Heavy damage requires professional repair, but minor bending can be combed out with a fin comb.
- Is there ice on the copper refrigerant lines? This means low refrigerant or an airflow problem — turn the AC off immediately and let it thaw.
Clear a 2-foot radius around the unit. Hose down the fins (outside only) to clean them.
4. Check the Breakers
Your AC has two breakers: one for the indoor unit (air handler), one for the outdoor unit (condenser). Both need to be on.
- Check the electrical panel for any tripped breakers
- Check the outdoor disconnect box (a small metal box on the wall near the outdoor unit) — there's a pull-out or switch inside
- If a breaker keeps tripping, STOP. That's a professional repair.
5. Check the Condensate Drain
Your AC produces condensation as it cools. That water has to go somewhere. If the drain line is clogged, a float switch shuts the system off to prevent water damage.
- Find the condensate pump or drain line near the indoor air handler
- Is there standing water?
- Is the float switch engaged?
- You can sometimes clear a clog with a wet/dry vacuum on the drain outlet
6. Check the Vents and Returns
- All supply vents in every room should be open
- Return vents (the big intake grilles) should NOT be blocked by furniture, rugs, or curtains
- Close basement/crawlspace vents are OK — closed upstairs vents are not (causes pressure issues)
7. Let the System Rest
If the AC has been struggling for a while, it may have shut down on a safety lockout. Turn it completely off at the thermostat and breaker. Wait 15-30 minutes. Turn everything back on in this order:
- Breaker on
- Thermostat to Cool, temperature set low
- Listen for outdoor unit to kick on within 5 minutes
8. Check for Refrigerant Line Frost
Look at the large insulated copper line running from the outdoor unit to the house. On a properly working AC, this line is cold but not frosty. If you see ice or frost on it:
- Turn off the AC immediately
- Let it thaw for 2-4 hours
- Try running it again
- If it frosts up again, you probably have a refrigerant leak or restricted airflow — call for service
When It's Definitely Time to Call For Service
After going through the 8 steps, call if:
- Outdoor unit won't start at all
- Breaker trips every time you turn the AC on
- Refrigerant lines keep frosting up
- You hear grinding, screeching, or banging from the unit
- Burning smell from vents
- Water leaking inside near the air handler
- AC runs constantly but temperature never drops
What a Professional Will Likely Find
- Low refrigerant (leak): Requires leak detection, repair, and recharge ($400-$1,500)
- Bad capacitor: $150-$400 repair
- Bad contactor: $150-$350 repair
- Bad fan motor: $400-$750 repair
- Failing compressor: $1,200-$2,800 repair (or replace unit)
- Frozen evaporator coil from airflow issue: Usually $150-$300 cleanup after fixing the root cause
For more on cost, see our HVAC repair cost guide.
Prevent Next Summer's Problem
Most AC issues in Fort Wayne are preventable with 30 minutes of prep in April or May:
- Replace the air filter
- Clean around the outdoor unit (clear debris, hose down fins)
- Have a professional AC tune-up in spring ($85-$175)
- Check and clean condensate drain line
- Inspect refrigerant lines for damage
See our HVAC maintenance schedule for the full seasonal checklist.
If you've tried everything and your AC still isn't cooling, call (260) 255-4551. Same-day diagnosis throughout Fort Wayne and Allen County.