Split AC repair on the Costa Blanca

Most common symptoms and causes

When AC stops cooling like it used to, several causes can look the same on the surface. The difference is the speed and shape of the failure. If efficiency dropped gradually over months, the likely cause is a slow gas leak progressively reducing the charge until the unit can’t work properly. If the AC was cooling normally and suddenly stopped putting out cold from one day to the next, it’s usually a big leak, compressor failure or control-board issue. If it starts but stops after a few minutes with an error code on the remote, it can be the thermostat, a temperature sensor or a communication issue between units.

Older non-inverter models start and stop abruptly at full power, stressing the compressor more. Modern inverter models modulate smoothly and last longer, but their electronics are more sensitive and from year seven or eight start showing board faults that require replacing the whole module. The repair-vs-replace call depends on part cost versus the price of an equivalent new unit.

The faults we see most on the Costa Blanca

Gas leak at the outdoor-unit fitting, especially on units over 5 years old. Salt air and summer-winter thermal cycles loosen fittings. A small leak progressively reduces the charge and the unit cools worse each season. Repair means professional gas detector, fitting replacement or copper re-soldering, vacuum and recharge.

Worn-out compressor on budget units with 6-9 years of intensive use. Most expensive failure. Compressor replacement costs a significant share of a new unit and only pays off on premium gear with reasonable life left. On basic units we typically recommend replacing.

Failed control board from surge, humidity or component aging. Relatively common in inland Vega Baja with August thunderstorms. Repair can be full board swap or, if isolatable, replacement of the specific capacitor or resistor. Depends heavily on model and parts availability.

Indoor fan blocked by dust build-up or worn bearings. When the fan doesn’t spin at the right speed, air doesn’t flow correctly over the coil and the room feels much warmer even though the unit is running.

The professional diagnosis process

We arrive with a full instrument kit: manifold gauges, contact and infrared thermometers, electronic gas leak detector, multimeter and clamp meter for electrical measurements, and brand-specific diagnostic apps to read error codes stored on the board.

Diagnosis starts with a brief client interview about when the problem started, how it shows, anything unusual just before (storm, unit relocation, knock). Continues with visual inspection looking for oil traces betraying leaks, mechanical damage and dirt build-up. Then electrical measurements and refrigeration analysis with manifold gauges. Once cause is identified, fixed-price repair quote compared with new-unit cost if the failure is major.

When to replace rather than repair

As a rule, if repair exceeds 60% of an equivalent new unit, it’s not worth it. The reason is repairing one expensive component leaves the rest at its real age, and the next components will start failing soon. Replacing the compressor on a 9-year-old unit at significant cost, knowing electronics and fans are also aging, is usually a poor investment.

For premium units (Mitsubishi, Daikin, LG) at 10-12 years, repair often still pays because overall quality justifies extending life. For budget units at 7-8 years, replacing is almost always the sensible call.