Memorial Day weekend is usually the first stretch in Houston where the AC runs hard for three days straight. By the Saturday of Memorial Day weekend, every working AC in Pearland, Friendswood, and the South Houston market is at 80 percent duty cycle or higher. Anything marginal that survived a mild April will surface that weekend.
The good news: most of the failures we get called for during the holiday weekend trace back to one of five things, and four of them are free or near-free to check on a Friday afternoon. About 30 minutes of homeowner time. Worth doing before the kids show up and the brisket goes on.
1. The filter
Single biggest spring win. A loaded filter starves the indoor coil of airflow, and once airflow drops far enough, the coil drops below 32°F and freezes. Once frozen, the system blows warm air at the registers and you call us on Sunday. We change the filter, defrost the coil for 4 hours, and bill you for the service call. All of that prevented by a $15 filter swap.
Pull the existing filter and hold it up to a light. If light does not pass through cleanly, it is past due. Houston pollen and pet dander load filters faster in spring than the manufacturer rating suggests; a "90-day" filter often needs replacing in 45 to 60 days during pollen season.
2. The outdoor condenser
The outdoor unit pulls air through the sides and exhausts up. The aluminum fins surrounding the coil have to be clean for the system to reject heat at design capacity. After spring, those fins are typically caked with pollen, grass clippings, and cottonwood seeds.
Turn the system off at the breaker first. Garden-hose the unit from the top down, opposite the direction the fan pulls air. Wait 10 minutes after rinsing before restoring power. Do this once in spring and once mid-summer, and the system will run measurably cooler all season.
3. The 2-foot clearance rule
Walk the outdoor unit. If grass has grown into the cabinet, if shrubs have crept within a foot of the side coils, or if you have stored anything against the unit (a ladder, a hose reel, mulch piled up), clear it. The unit needs 2 feet of free space on every side and 5 feet above. Mulch packed against the cabinet is the single most common installation-side problem we find on tune-up calls in late spring.
4. The thermostat test
Friday afternoon, when outdoor temps are in the 80s or 90s, drop the thermostat 4 degrees below current indoor temp. Within 5 minutes you should hear the indoor blower start and feel cold air at the registers. If the system does not start at all, or the air at the registers feels neutral or warm, you have a problem. Catching a non-starting system on Friday afternoon is the difference between a $189 service call Monday and a $400+ emergency call Saturday.
Common Friday-afternoon failures: a tripped breaker, a dead capacitor, a stuck contactor, a low refrigerant charge. The first one you can fix yourself; the other three are 30-minute service calls if we get to them before the weekend.
5. The temperature split
This one takes a thermometer. After the system has run 10 to 15 minutes, hold a thermometer at the return air grille (where the system pulls air in) and at the closest supply register (where it blows out). The supply should read 15 to 20 degrees cooler than the return.
Under 15 degrees: low refrigerant charge, low airflow, or a dirty evaporator coil. Over 22 degrees: airflow restriction (often a kinked duct, a closed register, or a partially blocked filter that is not fully loaded yet). Either reading is a reason to call before Memorial Day, not after.
What to skip
Do not open the indoor unit unless you know what you are looking at. Do not pour bleach down the condensate drain line; the right product is a teaspoon of distilled white vinegar through the cleanout port. Do not "top off" the refrigerant yourself; on R-410A systems that requires EPA Section 608 certification, and on the new R-454B systems the chemistry is different enough that a wrong-product top-off can damage the compressor.
If the checklist surfaces a problem
Call 281-992-7866 or book online. We hold extra capacity on the schedule from Memorial Day through Labor Day for service calls in the South Houston area. Clear Advantage members get same-week scheduling on cooling outage calls; non-members go in the standard queue, typically 24 to 72 hours during peak summer.
AC making noise it shouldn't, or not keeping up? Pre-Memorial-Day service calls are the cheapest of the season. 281-992-7866 or book online.