St. Louis summers are no joke — 90-degree days start in June and don't let up until September. If your AC hasn't been looked at since last year, now is the right time to run through a few basics before that first real heat wave hits.
Most AC breakdowns during summer aren't random — they're the result of small problems that went unnoticed over winter and spring. A little attention in May can save you from a $300 emergency service call in July (or worse, a full week without cooling while waiting on a part).
Here's exactly what we check when we do a summer tune-up at Lolich, along with the things you can handle yourself.
What You Can Do Yourself
You don't need to be an HVAC tech to take care of the basics. These five tasks take less than an hour and make a real difference in how your system performs.
1. Replace the Air Filter
This is the single most impactful thing a homeowner can do. A clogged filter restricts airflow, makes the system work harder, reduces cooling efficiency, and can cause the evaporator coil to freeze up. In St. Louis, where AC runs constantly all summer, most homes need a filter change every 1–2 months during peak season. If you can't see light through the filter when you hold it up, it's time for a new one.
2. Clear the Area Around Your Outdoor Unit
The outdoor condenser unit needs clear airflow to work properly. Over winter and spring, debris, tall grass, and overgrown shrubs can block the coil. Shut off power to the unit, then clear at least 18–24 inches of space on all sides. You can also gently rinse the outside of the coil with a garden hose to remove dust and debris — spray from the inside out if possible.
3. Check Your Condensate Drain Line
Your AC pulls humidity out of the air, and that moisture drains through a condensate line. In summer, these lines can clog with algae and mold — especially in St. Louis's humid climate. A clogged drain can cause water damage or trigger a safety shutoff that stops your system cold. Pour a cup of diluted bleach (one part bleach, three parts water) down the drain line once a month to keep it clear.
4. Test the System Before You Need It
Turn on your AC on a mild day — not during the first 95-degree heat wave. Set it to cool and let it run for 15–20 minutes. Check that cold air is coming out of the vents, the outdoor unit is running, and there are no unusual sounds or smells. If something seems off, you want to find out now, not when it's 98 degrees and every HVAC company in St. Louis is slammed.
5. Check Your Thermostat Settings
Make sure your thermostat is set to "cool" (not "heat" or "fan only"), the temperature is set lower than the current room temperature, and the fan is set to "auto" rather than "on." If you have a programmable thermostat, review your summer schedule. Most St. Louis homeowners see real energy savings by setting the temperature a few degrees higher when they're out of the house.
What a Professional Tune-Up Covers
The DIY steps above handle the basics. But there are things that require a licensed tech — measuring refrigerant charge, checking electrical components, and inspecting the coils properly. Here's what we check during a professional AC tune-up:
Signs Your AC Needs More Than a Tune-Up
A tune-up is preventive maintenance — it's not a repair. If you're already seeing any of these symptoms, you're past the tune-up stage and need a diagnostic call:
How Often Should You Schedule a Tune-Up in St. Louis?
Once a year is the standard recommendation — and spring (before the heat arrives) is the right time. Given how hard St. Louis summers push AC systems, annual maintenance pays for itself in avoided repairs and extended equipment life. If you also have a gas furnace, fall is the time to schedule that tune-up before heating season.
If your system is 10+ years old or has had repairs in the past couple of years, annual tune-ups become even more valuable. They let you catch declining components before they fail at the worst possible time.
Schedule Your Summer AC Tune-Up
We do AC tune-ups throughout the St. Louis area — Chesterfield, Ballwin, Wildwood, Ellisville, and surrounding communities. Book before the summer rush hits and you'll get the appointment time you want. If we find anything concerning during the tune-up, we'll tell you exactly what it is and what it will cost to fix — no pressure.