Air conditioning in southern Spain isn't a seasonal luxury — it's running for eight or nine months of the year. That kind of workload puts any system under real strain. The question most homeowners ask us isn't whether to maintain their AC, but when. The answer is more specific than most people expect.
The short answer: service it in spring
The single most important service window on the Costa del Sol is April or early May, before the first heat arrives. By the time temperatures climb into the mid-30s in June, your system needs to be running at full efficiency. Servicing in spring means any issues — blocked filters, low refrigerant, worn fan bearings, dirty coils — are found and fixed before the system is under peak load.
A system that goes into summer with a partially blocked condenser coil or a refrigerant charge that's 10% low will work harder, consume more electricity, and cool less effectively. Over a full summer season, that inefficiency adds up to a meaningful difference on your electricity bill.
Rule of thumb: If your AC hasn't been serviced in 12 months, book it for April. Don't wait until it stops working in July — lead times in summer can run to several weeks.
What happens in a professional AC service
A proper maintenance visit is considerably more than cleaning the filters — though that matters too. When our engineers carry out a full service, they work through a structured checklist that covers both the indoor and outdoor units:
- Indoor unit: Filter cleaning or replacement, coil cleaning, condensate drain inspection and flush, fan and blower check, electrical connections check
- Outdoor unit: Condenser coil cleaning, fan motor inspection, refrigerant charge check, casing and fixings inspection
- System test: Temperature differential check across the unit, operating pressures, check all operational modes (cooling, heating, fan, dry, auto), thermostat and remote calibration, fault code scan
Most of these checks can only be done properly with the right equipment — a refrigerant manifold gauge set, clamp meter, and access to the manufacturer's diagnostic software. A "service" that consists only of cleaning the filters is not a service.
How often do you actually need it?
The official manufacturer recommendation for residential split systems is once a year. For systems that run heavily — a villa that's occupied most of the year, or a property close to the coast where salt air accelerates corrosion — we suggest twice a year: once in spring before summer, and once in autumn before the heating season begins.
| Property type | Recommended frequency | Best timing |
|---|---|---|
| Primary residence, year-round use | Twice a year | April + October |
| Holiday home, summer use | Once a year | April / early May |
| Holiday home, occasional use | Once a year minimum | Before each main stay |
| Coastal property (salt air exposure) | Twice a year | April + October |
| Commercial premises | Quarterly | Feb / May / Aug / Nov |
The hidden cost of skipping a service
A service contract with Oasis costs a fraction of what a single repair call-out costs in high season. The most common consequences of deferred maintenance we see in the field are:
- Compressor failure — the most expensive single component in any AC system. Almost always preceded by warning signs (reduced cooling, unusual noise, high current draw) that a service would catch.
- Blocked drain lines — cause water damage to ceilings and walls. A €30 fix if caught early; potentially a €2,000 plastering and painting job if not.
- Dirty condenser coils — force the compressor to work at higher pressures, reducing efficiency by up to 30% and accelerating wear.
- Refrigerant leaks left to develop — a small leak found during a routine service is a straightforward repair. The same leak left for a second summer can damage the compressor.
What about the filters — can I do those myself?
Yes, and you should. The washable filters on the indoor unit should be removed and rinsed every four to six weeks during periods of heavy use. Let them dry fully before refitting. This is the one maintenance task that genuinely doesn't need an engineer, and doing it regularly makes a real difference to air quality and efficiency.
What it doesn't replace is the annual professional service — filter cleaning doesn't touch the coils, refrigerant charge, electrical connections, or any of the components inside the outdoor unit.
Maintenance contracts
If you have more than one system, or if you'd rather not have to remember to book each year, a maintenance contract is the simplest solution. Our contracts cover annual visits, priority call-out in the event of a breakdown, and discounted labour on any repairs required. We cover the full western Costa del Sol — Marbella, Estepona, Sotogrande, Fuengirola and everything in between.
Get in touch to discuss a contract for your property.