Why air conditioning stops cooling over time

The A/C circuit isn't 100% sealed: refrigerant gas runs through rubber hoses, O-rings and fittings, and minute amounts of gas seep through those materials even with no fault present. It's normal wear, not a defect — but it has a limit: below a certain pressure, the compressor stops engaging, or the system simply doesn't have enough "body" left to cool the cabin.

That's why manufacturers recommend a preventive recharge every 2 years, symptoms or not. Waiting until it "barely cools at all" usually means the system has spent months running well below capacity, forcing the compressor unnecessarily.

6 signs your air conditioning needs checking

  1. Little or no cooling — especially if you only feel some cold air with the fan on maximum.
  2. Takes a long time to cool the cabin — in summer, with the car parked in the sun, you should feel it within 1–2 minutes. Longer than that means the system is low or the condenser is dirty.
  3. Noise or vibration when the compressor engages — squealing, or the compressor cutting out on its own, can point to a failing electromagnetic clutch or the compressor itself.
  4. Bad smell on start-up — a musty, damp smell points to bacteria and mould in the evaporator, not a gas problem.
  5. Water dripping inside the car — the A/C condenses water that should drain outside; if it's dripping at the passenger's feet, the drain is blocked.
  6. More than 2 years since the last recharge — even if it still cools "okay" for now, this is the most reliable sign it's already below factory capacity.
What many people don't know

Not every car uses the same gas. Models up to roughly 2016–2017 use R134a; most newer cars use R1234yf, a pricier gas that needs a different charging station. Topping up an R1234yf system with R134a isn't just ineffective — the two are incompatible and can damage the circuit. If you're not sure which one your car uses, tell us the make, model and year and we'll confirm it before touching anything.

Why quick "recharge in a can" sprays almost never fix anything

Aerosol recharge cans from the petrol station are the most tempting option because they look cheap and fast — but they almost never solve the actual problem. If there's a leak, the gas from the can escapes exactly the way the original did, sometimes within weeks. And if the can contains "leak-stop" additives, they can clog the expansion valve or mix badly with the compressor oil, complicating a proper repair later on.

It's a saving of €15–20 that, if there's a genuine leak, turns into a repeat recharge every few months — more expensive in the long run than tracking down and fixing the actual leak once.

How we find the leak before recharging

We connect the charging station to the circuit and measure pressures cold and running: that alone tells us whether it's normal gradual loss or an active leak. If there are signs of a leak, we use a UV tracer — a dye that circulates with the system oil and, under UV light, points to the exact spot: a seal, a hose, the condenser or the evaporator itself.

Once we've found it, we tell you what needs repairing and what it costs before recharging anything. Recharging a system with an active leak, without repairing it, just wastes the gas — it'll be gone again within a few weeks.

What an A/C recharge costs in Valencia (2026)

Indicative prices, including system vacuum, refrigerant oil and a cooling test:

  • Recharge with R134a (no leak detected): ~€65–90
  • Recharge with R1234yf (newer cars, pricier gas): ~€90–130
  • Leak detection + repair, depending on the component affected (seal, hose, condenser, compressor): ~€80–300 extra
  • Evaporator ozone sanitising (optional, removes bacteria and odours): ~€35–50

If a quote is well below these ranges, ask whether it includes a system vacuum and a leak check — a plain "blind top-up" without those two steps doesn't tell you anything about how long it'll actually last.

One simple habit that extends the system's life

A very common mistake is switching the A/C off entirely in winter "to save fuel". The problem is that the compressor's seals and gaskets are lubricated by the refrigerant oil circulating through the system — if it sits unused for months, those seals dry out slightly and are more likely to start leaking earlier than they should.

The fix is simple: run the air conditioning for about 10 minutes every 2–3 weeks, in winter too — even with the temperature turned all the way up so you don't freeze. It keeps the compressor lubricated, the seals flexible, and lowers the odds of a premature leak — the cheapest way to stretch the time between recharges.

What we do at 2 Hermanos

We run our air conditioning service with an approved charging station, scale and automatic vacuum, and we work with both gases (R134a and R1234yf). If there's a leak, we tell you exactly where and give you a fixed quote before touching anything — we never recharge a leaking system without warning you first.

Isn't your A/C cooling like it used to? Message us on WhatsApp with the make, model and year — we'll confirm which gas your car uses and give you a fixed price.