In Houston, Memorial Day weekend is usually the first stretch where the AC runs hard three days straight. By that Saturday, air conditioners across Pearland and Friendswood are running most of the day. Anything marginal that squeaked through a mild April shows itself that weekend.
Most of the holiday-weekend failures we get called for trace back to one of five things, and four of them cost little or nothing to check. Give it about 30 minutes on Friday afternoon, before the kids show up and the brisket goes on.
1. The filter
This is the biggest spring win. A loaded filter starves the indoor coil of air. Once airflow drops far enough the coil falls below 32°F and freezes, the registers start blowing warm air, and you call us on Sunday. We change the filter, let the coil thaw for about 4 hours, and you pay for a service call that a $15 filter would have prevented.
Pull the filter and hold it up to a light. If light doesn't come through cleanly, it's past due. Houston pollen and pet dander clog filters faster in spring than the rating on the package suggests. During pollen season a "90-day" filter often needs changing at 45 to 60 days.
2. The outdoor condenser
Air goes in through the sides of the outdoor unit and out the top. For the coil to shed heat properly, the aluminum fins around it have to be clean, and by late spring they're usually caked with pollen, grass clippings and cottonwood seed.
Shut the system off at the breaker first. Hose the unit from the top down, against the direction the fan pulls air, then wait 10 minutes before turning the power back on. Do it once in spring and again in midsummer and the system runs cooler all season.
3. The 2-foot clearance rule
Walk around the outdoor unit. Clear out any grass growing into the cabinet and cut back shrubs creeping toward the side coils. Move the ladder or hose reel leaning on it. The unit needs 2 feet of open space on every side and 5 feet above. On late-spring tune-ups, mulch packed against the cabinet is the install-side problem we run into most.
4. The thermostat test
Friday afternoon, with the outside temperature in the 80s or 90s, set the thermostat 4 degrees below the indoor temperature. Within 5 minutes the indoor blower should start and cold air should come out of the registers. If nothing starts, or the air feels neutral or warm, something is wrong. Find it Friday and a tech can often get there before the weekend. Find it Saturday and you're in line with everyone else in town. Our price is the same either day.
Typical Friday-afternoon culprits are a tripped breaker, a dead capacitor, a stuck contactor or a low refrigerant charge. You can reset the breaker yourself. The other three are quick repairs if we get to them before the weekend.
5. The temperature split
You'll need a thermometer. After the system has run 10 to 15 minutes, take a reading at the return air grille, where the system pulls air in. Then take one at the closest supply register, where it blows out. The supply should be 15 to 20 degrees cooler than the return.
Under 15 degrees points to a low refrigerant charge or low airflow, or a dirty evaporator coil. Over 22 usually means an airflow restriction such as a kinked duct or a closed register, sometimes a filter that is partly clogged. Either reading is a reason to call before Memorial Day.
What to skip
Leave the indoor unit closed unless you know what you're looking at. Don't pour bleach down the condensate drain line. Distilled white vinegar through the cleanout port is the right product. And don't "top off" the refrigerant yourself. On R-410A systems that takes EPA Section 608 certification, and the newer R-454B systems are different enough that the wrong product can damage the compressor.
If the checklist surfaces a problem
Call 281-992-7866 or book online. From Memorial Day through Labor Day we hold extra room on the schedule for service calls around South Houston. Clear Advantage members get moved to the front of the line on cooling outages, and everyone pays the same price nights and weekends.
The easiest service call of the season is the one booked before Memorial Day. Beat the June rush at 281-992-7866 or book online.