Before the first hot week, check HVAC airflow, clear the outdoor unit, test cooling mode, inspect the condensate drain, and schedule service if the system is due. Do it while appointments are still easier to get.
Spring HVAC prep checklist
- Check the air filter and replace it if dirty.
- Clear debris and storage from around the outdoor unit.
- Rinse dirty outdoor coils gently if needed.
- Test cooling mode before you need it.
- Check the condensate drain and emergency pan.
- Open supply vents and make sure returns aren't blocked.
- Check thermostat settings and batteries.
- Schedule professional service if the system is due or acting strange.
Start with the filter
A dirty filter reduces airflow and makes cooling harder. Check it before regular AC use starts. Replace it if it is gray, bowed, clogged, or the wrong size.
Save the size printed on the filter frame. Install the filter with the airflow arrow pointing toward the furnace or air handler.
Clear debris and storage from around the outdoor unit
The condenser needs open airflow. Remove leaves, weeds, grass clippings, and anything stored too close to the unit. About 2 feet of clearance is a practical target where space allows.
Pay extra attention if the unit sits under trees or near a deck — leaves and pollen can pile up fast in spring and choke the airflow.
Rinse dirty outdoor coils gently
If the coil is covered in dirt, pollen, or cottonwood fluff, turn the system off and rinse from outside in with a garden hose on a normal spray setting. Don't use a pressure washer — the fins bend easily, and bent fins reduce airflow. If the coil is heavily fouled or you see oily residue, that's a job for a service tech.
Test cooling mode early
Pick a mild day and run the AC for 15 to 20 minutes. Check that cool air comes from vents, the outdoor unit starts, and nothing sounds wrong.
If the system blows warm air, short cycles, trips a breaker, leaks water, or makes new grinding or buzzing sounds, stop and book service before the first heat wave.
Check the condensate drain and emergency pan
Air conditioners remove moisture from indoor air. That water should drain safely. Look for standing water near the indoor unit, a wet emergency pan, musty smells, or signs that a float switch has shut the system off.
A clogged drain can cause water damage or shut down the equipment until the drain is cleared.
Open supply vents and check returns
Open supply vents and make sure return grilles aren't blocked by furniture, rugs, or storage. Good airflow is part of the system, not decoration. A blocked return makes the system work harder and can contribute to uneven cooling or icing.
Check thermostat settings and batteries
Check thermostat mode, schedule, batteries, and temperature reading. A bad schedule can look like an AC problem when it is really a settings problem. Replace batteries on battery-powered thermostats every year or two; a dying battery can cause erratic behavior before it finally dies.
Schedule professional service if the system is due
Schedule service if the system has not been checked in a while, struggled last summer, freezes, leaks, makes new noises, or can't cool evenly. Call sooner for electrical smells, repeated breaker trips, or any sign of refrigerant line ice. Spring is the right time to do this — by mid-summer every tech in town is booked solid.
Good maintenance rhythm
- Spring: filter, outdoor unit, cooling test, condensate check, thermostat check.
- Monthly in heavy use: check the filter.
- After storms: clear debris around the outdoor unit.
- As needed: professional service for poor cooling, electrical issues, ice, leaks, or unusual noise.