How to prep your system for a DMV summer
May 6, 2026 · 6 min read · Updated June 2026
DMV summers don't ease in — one week it's pleasant, the next it's 95° with swamp humidity and your AC is running nonstop. The breakdowns we see in July almost always trace back to something that could've been caught in May. A little prep now saves you a miserable, expensive week later.
1. Change the air filter
It's the simplest thing and the most neglected. A clogged filter chokes airflow, makes your system work harder, drives up your bill, and can freeze the coil. Check it monthly during peak season and swap it when it looks dirty — a clean filter is the cheapest comfort upgrade there is. Not sure which to buy? Our guide to air filters and MERV ratings explains how to match the filter to your system.
2. Clear the outdoor unit
Your condenser sits outside and needs to breathe. Over winter and spring it collects leaves, grass clippings, pollen, and cottonwood fluff. Cut back any plants to give it about two feet of clearance on all sides, and gently rinse the fins with a garden hose (power off first). Restricted airflow out there is one of the top causes of a system that "can't keep up."
3. Check the condensate drain
Your AC pulls a lot of moisture out of our humid air, and that water drains away through a line that loves to clog with algae. A backed-up drain can shut the system down or leak water near your furnace or air handler. If you're handy, a wet/dry vac on the drain line outlet clears most clogs; if you'd rather not, it's a standard part of a tune-up.
4. Test it before you need it
Don't let the first 95° day be the first time you run the AC. On a mild day, switch it to cool and drop the thermostat a few degrees. You want cold air at the vents within a few minutes and no odd smells, rattles, or short-cycling. Finding a problem on a 70° day is a scheduled repair; finding it during a heat wave is an emergency call. If it isn't cooling right, our guide to DMV AC repair walks you through the next step.
5. Mind the thermostat
Fresh batteries if it's battery-powered, and if you've got a programmable or smart thermostat, set a schedule that eases off while you're out and cools down before you're home. Many DMV utilities even offer rebates on smart thermostats — a small change that trims a long cooling season's bill.
6. Keep your vents open and the drain clear all season
Once summer's running, two easy habits keep it efficient: leave your supply and return vents open (closing off too many rooms raises duct pressure and strains the blower), and keep an eye on the condensate line — a musty smell or water near the air handler means it's starting to clog. These are the homeowner basics; refrigerant, electrical work, and a coil that keeps freezing should always go to a technician.
The one job to leave to a pro
The DIY steps above keep airflow clean and catch the obvious stuff. A professional tune-up goes further — checking refrigerant charge, electrical connections, capacitor health, and safety controls. That's where we catch the failures before they leave you sweating. Our Comfort Club members get this done automatically every spring.
Beat the rush
The best time to get a tune-up is before everyone else needs one. Once the first heat wave hits, the whole region calls at once. Get on the schedule early and head into summer knowing your system is ready. We cover the neighborhoods on our DMV service map.
Frequently asked questions
When should I prep my AC for summer in the DMV?
Early spring, before the first heat wave. Our region jumps from heating to cooling in a hurry, and that fast transition is exactly when a system that sat all winter reveals a weak capacitor, a low charge, or a clogged drain. Catching it in April beats discovering it in a July heat wave — and you'll get a better tune-up slot before everyone calls at once.
What AC maintenance can I do myself?
Plenty: change the air filter, keep two feet clear around the outdoor unit and gently rinse the fins with a garden hose (power off), keep your vents open, watch the condensate line, and program the thermostat. Those simple habits keep cooling efficient through a humid DMV summer.
What should I leave to a technician?
Anything that needs gauges, training, or an EPA refrigerant certification: checking or adding refrigerant, electrical repairs (capacitors hold a charge), a coil that keeps freezing, and the full multi-point tune-up that measures charge, electrical, and airflow. Comfort Club members get two professional tune-ups a year scheduled automatically.
Ready for a pre-season tune-up? We'll get you on the books before the rush.