Most HVAC problems give warning signs long before they leave you without air. This checklist covers everything a homeowner can safely do through the year — tap each item to check it off (your progress saves on this device), or print it and stick it on the fridge. Items marked PRO need a licensed technician.
Every Month
- Check the air filter. Replace 1" filters every 1–3 months — monthly if you have pets, allergies, or construction nearby.
- Pour a cup of white vinegar down the condensate line (at the cleanout tee near the indoor unit) to slow algae buildup.
- Look at the drain pan and float switch. Standing water = clog in progress.
- Walk the supply and return vents. Nothing blocking them — furniture, rugs, or closed dampers.
- Glance at the outdoor unit. Keep 2 feet clear on all sides; pull weeds and debris.
Every Season
- Test the thermostat — set it 5° lower (or higher) and confirm the system starts within a few minutes.
- Replace thermostat batteries if it uses them.
- Gently rinse the outdoor coil with a garden hose (power off at the disconnect first — no pressure washer).
- Check the refrigerant line insulation outside. Cracked or missing foam costs efficiency.
- Listen for new noises — buzzing, rattling, squealing, or clicking that wasn't there before.
- Compare your energy bill to the same month last year. A jump of 15%+ is worth a look.
Spring: Before the Heat Hits
- Fresh filter before the first hot week.
- Run the AC on a mild day to make sure it cools before you really need it.
- Check the temperature split: air at a supply vent should be about 15–20°F cooler than the return.
- Trim shrubs and fences back from the condenser.
- Cooling tune-up — capacitor test, coil cleaning, refrigerant check, drain flush. PRO
Summer: Peak Load
- Keep a steady setpoint (78°F when home is the efficient sweet spot). Big swings make the system run harder.
- Watch for ice on the copper line or indoor coil — turn the system to fan-only and call.
- Check the drain line monthly — summer is when it clogs.
- Close blinds on sun-facing windows in the afternoon.
Fall: Heating Prep
- Test the heat before the first cold front. A little dust smell is normal for a few minutes.
- Test carbon monoxide detectors and replace batteries — required peace of mind with gas heat.
- Clear the furnace area of storage, paint, and anything flammable.
- Heating inspection — heat exchanger, flame sensor, gas pressure, CO test. PRO
Winter: Freeze Readiness
- Heat pump owners: some steam during defrost is normal; a solid block of ice is not.
- Keep snow and ice off the outdoor unit during the rare Texas freeze.
- Know where your shutoffs are — breaker, outdoor disconnect, and gas valve.
Once a Year (or as Needed)
- Duct inspection for disconnected or crushed runs in the attic. PRO
- Electrical check on contactor, wiring, and disconnect. PRO
- Review system age. 12+ years? Start planning — read our Replacement Guide.
- Keep a service log: dates, filter sizes, model and serial numbers, and who serviced it.
Stop & call a pro if you notice
- A burning or electrical smell, or a breaker that keeps tripping
- A rotten-egg (gas) smell — leave the house and call your gas utility first
- Water leaking from the ceiling or indoor unit
- The outdoor fan not spinning while the unit hums
- Your CO alarm going off — get outside and call 911
Let us handle the PRO items
Our preventive maintenance plans cover every PRO item above, twice a year, with a written report. Call (830) 252-9000.
Quick Answers
How often should I change my AC filter in Texas?
Check it monthly. Standard 1-inch filters usually need replacing every 1 to 3 months; homes with pets or allergies should lean toward monthly.
Can I clean my own AC coil?
You can gently rinse the outdoor coil with a garden hose after shutting off power at the disconnect. Indoor coil cleaning and refrigerant work should be left to a licensed technician.