Skip to content 
Washington summers can catch homeowners off guard. One week you’re reaching for a jacket, and the next you’re flipping on the air conditioner for the first time in months only to find it blowing warm air or making a grinding noise you don’t remember from last year.
The good news is that a simple AC tune-up checklist can prevent most of those surprises before the heat hits. Whether you’re in Kent, Renton, or anywhere else in King County, taking care of your cooling system before summer arrives is one of the smartest home maintenance moves you can make.
This guide walks you through everything Washington homeowners should check before turning on the AC for the season and flags a few things best left to a professional.
Your 6 Point AC Maintenance Checklist
1. Replace or Clean Your Air Filter
Your air filter is the single easiest thing you can check, and one of the most impactful. A clogged filter forces your air conditioner to work harder, raises your energy bills, and can lead to a frozen evaporator coil which shuts the whole system down. For most Washington homes, a 1–3 inch filter should be replaced every 1–3 months during the cooling season.
Before the season starts, pull the filter out, hold it up to the light, and check for heavy dust buildup. If you can’t see light through it, it’s time for a new one. If you have pets or family members with allergies, consider upgrading to a MERV-11 or MERV-13 rated filter for better air quality all summer long.
2. Clear the Area Around Your Outdoor Condenser Unit
After Washington’s wet winters and springs, your outdoor condenser unit has likely accumulated leaves, debris, and possibly some weedy growth around it. Your condenser needs at least two feet of clear space on all sides to breathe properly. Restricted airflow around the unit causes the system to overheat and run inefficiently.
Clear away any vegetation, trim back nearby shrubs, and gently rinse the condenser fins with a garden hose (from the inside out if possible) to remove dirt and debris. Don’t use a pressure washer; the fins bend easily and can reduce airflow just as badly as blockage.
3. Test Your Thermostat Before You Need It
It sounds obvious, but many homeowners don’t test their thermostat until the first really hot day, and that’s when problems get stressful. Turn your system to “cool” mode, set the temperature 5 degrees below the current room temperature, and listen for the system to kick on within a minute or two.
If you have an older thermostat, spring is also a great time to upgrade to a programmable or smart thermostat. Many Washington homeowners are surprised by how much they can save on energy bills by setting cooling schedules that match their actual home time.
4. Check and Clear Your Condensate Drain Line
As your AC cools the air, it removes humidity, and that moisture drains out through a condensate line. In Washington’s climate, algae and mold love to grow in these lines during the off-season, causing blockages that can lead to water damage inside your home.
Locate the drain line (usually a white PVC pipe near the air handler), and pour a cup of diluted white vinegar into the access port to kill any buildup. If you notice water pooling near your indoor unit or a musty smell when the AC runs, the drain line may already be clogged a job for a professional HVAC contractor.
5. Inspect Your Ductwork and Vents
Walk through your home and make sure all supply and return vents are open and unobstructed. Furniture, rugs, and curtains covering vents create pressure imbalances that reduce efficiency and comfort. While you’re at it, check any visible ductwork in the attic, basement, or crawl space for obvious gaps, disconnections, or visible damage.
Leaky ducts are one of the most common hidden energy wasters in Washington homes. According to the EPA, typical homes lose 20–30% of conditioned air through duct leakage. If you suspect significant leakage, ask your HVAC technician about duct sealing services — Breeze Heating Air & Electrical offers AeroSeal duct sealing, which can dramatically improve system efficiency.
6. Schedule a Professional AC Tune-Up
The items above are great for homeowner maintenance, but an annual professional AC tune-up goes much deeper. A certified HVAC technician will check refrigerant levels, inspect electrical connections, clean the evaporator and condenser coils, lubricate moving parts, and test system performance from end to end. In Washington’s climate, the window for AC tune-up appointments fills up fast once May arrives, scheduling in March or April ensures you get in before the rush.
Think of a professional tune-up the same way you think about a car oil change: skipping it might seem like saving money in the short term, but it almost always leads to bigger repair bills and a shorter system lifespan.
Stay Comfortable All Summer — Starting Now With Breeze Heating Air & Electrical
Washington summers are short, and every homeowner deserves to enjoy them without worrying about a failing AC system. By running through this AC tune-up checklist before the heat arrives, you’ll catch small problems early, keep your energy bills in check, and give your system the best chance of running all season reliably.
If you’re in Kent, Renton, or anywhere in King County, the team at Breeze Heating Air & Electrical is ready to help. From professional tune-ups to full system inspections, Breeze makes it easy to get your home summer-ready.
Call or book an appointment online to schedule your appointment before the season heats up!
