HVAC Maintenance in San Diego That Measures Instead of Glances

The point of HVAC maintenance is to find the part that is about to fail while it is still cheap to replace, confirm the system is delivering its rated capacity, and keep the manufacturer warranty documented. That takes instruments. The checklist below is what a Superior Air technician does on a cooling tune-up; heating tune-ups add the combustion and ignition items at the end.

The tune-up checklist

1. Refrigerant charge: pressures, superheat and subcooling against the manufacturer’s chart, not a guess from the gauge. Low charge is a leak, and we say so rather than topping off.
2. Capacitor test: measured microfarads against the rating. A capacitor outside its tolerance is replaced before it strands the compressor.
3. Contactor: contact pitting, coil pull-in and debris. Ants and lizards in outdoor contactors are a genuine San Diego problem.
4. Amperage draw: compressor, condenser fan and blower amps against nameplate. Rising amps are the earliest warning of a failing motor or a restricted coil.
5. Condenser coil condition: cleaned of cottonwood, dust and salt film. Coastal condensers in Point Loma, La Jolla and Carlsbad corrode faster; we note fin condition.
6. Evaporator coil: inspected for biological growth, restriction and ice history; cleaned when accessible.
7. Condensate drain: cleared, flushed and treated; float switch tested; pan checked for rust or standing water in attic units.
8. Blower assembly: wheel cleanliness, motor bearings, belt where present, ECM operation and static pressure.
9. Filter: size, rating and fit. An undersized return or a too-restrictive filter is one of the most common causes of iced coils.
10. Thermostat calibration: reading against a reference thermometer, wiring at the board, program and staging settings.
11. Temperature split: supply versus return air across the coil. The single quickest check of whether the system is doing its job.
12. Duct connections: visible plenum and takeoff connections, boots and insulation at the equipment. Attic ducts in 1970s and 1980s tract homes are where most leaks live.
13. Safety controls: high-pressure and low-pressure switches, float switch, limit switches, and the disconnect and wiring condition at the condenser.
14. Heat exchanger and ignition (furnaces): heat exchanger inspection for cracks, igniter and flame sensor condition, gas pressure, flue and combustion air, and a carbon-monoxide check at the registers.

How often, in this climate

Coastal Zone 7 homes that only cool for a few weeks a year can go with a single spring tune-up. Inland Zone 10 homes in Escondido, Poway, Santee and El Cajon run cooling hard from June to October and should have the cooling visit in spring; if the same home relies on a furnace or heat pump for heat, a fall visit covers the heating checks. Filters are a separate matter: every one to three months depending on the filter type, pets and dust, and you can do those yourself. Our article on AC lifespan in San Diego covers what maintenance does and does not add to equipment life.

What maintenance cannot fix

A tune-up restores design performance; it does not change the design. It will not make an undersized system keep up with a heat wave, quiet an oversized one that short-cycles, cool a bedroom at the end of a leaky attic duct run, or bring a 20-year-old 10-SEER condenser anywhere near current SEER2 efficiency. When the readings show one of those problems, we write it up and point you at duct evaluation or replacement rather than scheduling another tune-up.