You schedule a tune-up. A tech shows up, spends 45 minutes to an hour at your house, and hands you a receipt. But what did they actually do? Was it worth it? Would you know the difference between a thorough tune-up and a quick once-over?
Here is exactly what our technicians do during a spring AC tune-up — step by step — and the most common problems we find in Triangle homes.
Step 1: Thermostat Check
We start inside. We verify your thermostat is reading accurately, cycling correctly, and communicating with the outdoor unit. We check the temperature differential between what the thermostat reads and what the actual room temperature is.
What we commonly find: Thermostats mounted on exterior walls or near windows giving false readings. Smart thermostats that lost their calibration after a firmware update. Old mercury thermostats that are 3-4 degrees off — your system has been running longer than necessary for years.
Step 2: Air Filter Inspection
We check your filter condition, size, and fit. A dirty filter is the single most common cause of AC problems, and a filter that does not fit properly lets unfiltered air bypass into the system.
What we commonly find in Triangle homes: 4-inch filters that have not been changed since the fall tune-up — six months of Triangle pollen, dust, and pet dander. Filters installed backwards (yes, direction matters). One-inch filters in systems designed for four-inch — restricting airflow and stressing the blower motor.
Step 3: Indoor Coil and Drain Inspection
We inspect the evaporator coil for dirt buildup and the condensate drain line for clogs. In the Triangle, this is one of the most important steps.
What we commonly find: Condensate drain lines clogged with algae and biofilm — Raleigh's humidity feeds this growth all summer. Dirty evaporator coils reducing cooling capacity by 10-20%. Drain pans with standing water because the line is partially blocked. Left unchecked, this causes water damage to ceilings and walls.
We flush the drain line and treat it to prevent buildup through the summer.
Step 4: Electrical Component Testing
We measure voltage, amperage, and test capacitors against their rated values. We inspect contactors for pitting or arcing, check wiring for heat damage or corrosion, and verify the control board is functioning properly.
What we commonly find: Capacitors that have degraded below spec — they lose 2-3% of capacity per year, and once they drop below 10% of rated value, the compressor or fan motor struggles to start. Contactors with pitting that will eventually weld shut or fail open. In older Triangle homes, rodent damage to wiring in attics and crawl spaces.
Step 5: Outdoor Unit Cleaning and Inspection
We clean the condenser coil, inspect the fan motor and blade, check the refrigerant line insulation, and clear debris from around the unit.
What we commonly find: This is where Triangle homes really show their environment. Condenser coils packed with pine pollen — Raleigh and Cary are notorious for it. Oak catkins and cottonwood fluff matted into the fins. Landscaping that has grown too close, restricting airflow. A coil caked with pollen can reduce efficiency by 30%.
We chemically clean the coil and rinse it thoroughly.
Step 6: Refrigerant Check
We measure suction and discharge pressures and calculate superheat and subcooling to verify your refrigerant charge is correct.
What we commonly find: Systems that are slightly low on refrigerant from slow leaks at service valve cores or brazed joints. The system still cools — it just runs longer and works harder to do it. On a 95-degree July day, that marginal charge becomes the difference between comfortable and not.
We also check for older systems still running R-22 (Freon) and advise on replacement timeline since the refrigerant is no longer manufactured.
Step 7: Airflow Verification
We measure the temperature split between return and supply air (should be 15-20°F for cooling) and check static pressure to make sure the blower is not fighting excessive resistance.
What we commonly find: Temperature splits outside the normal range — usually indicating a dirty coil, low refrigerant, or airflow restriction. High static pressure from undersized return ducts, which is extremely common in Triangle homes built during the 2000-2010 building boom when ductwork was often undersized to save on construction costs.
Step 8: Safety Checks and System Test
We run the full system through a cooling cycle, verify it starts, runs, and shuts off properly. We check for unusual noises, vibrations, or odors. We test the disconnect and verify the system meets NC safety code.
What a Tune-Up Catches (Real Examples)
Here are actual findings from spring tune-ups we have performed in the Triangle this year:
- Apex home, 2008 Carrier system: Capacitor at 62% of rated value. Compressor starting but struggling. Without replacement, the compressor would have failed mid-summer. Capacitor replacement: $150-$250. Compressor replacement: $2,000-$3,000.
- Cary home, 2014 Trane system: Condensate drain completely blocked. Drain pan full. Another week and it would have overflowed into the ceiling below. Drain flush: included in tune-up. Water damage repair: $1,500-$4,000.
- Raleigh home, 2011 Rheem system: Contactor pitted and arcing. System still running but the contactor was close to welding shut — which would run the compressor continuously until it burned out. Contactor replacement: $120-$200. Compressor replacement: $2,000-$3,500.
When to Schedule
March or early April. Here is why:
- Pollen peaks in April. If we clean your coil in March, it stays clean for the start of cooling season. Clean it in May and it is already coated.
- Schedules fill fast. By May, every HVAC company in Wake County is booked with emergency calls. Tune-up appointments get pushed to June or later.
- First hot days come early. The Triangle regularly sees 85°F+ in late April. You want your system tested before you need it, not after.
What It Costs
A standalone spring tune-up typically runs $89-$199 depending on system type and complexity.
Our Comfort Club members get two tune-ups per year (spring + fall) included, plus 15% off all repairs, priority scheduling, and no diagnostic fees. Contact us for current plan pricing.
The math: a single tune-up that catches a $180 capacitor before it kills a $2,400 compressor pays for itself and the next ten tune-ups.
Call us at 919-926-1475 to schedule your spring tune-up.
