Air Conditioning Repair Cost Calculator
Pick the symptom and this prices the likely repair, then tells you honestly whether a unit of that age is worth fixing at all.
Open the calculator →Price your AC fault in 30 seconds
4 steps. Symptom, unit age, urgency and region — with a repair-or-replace steer.
How this calculator works
The calculator prices by symptom, because that is all you can know before an engineer looks. Note any error code on the indoor display or remote first — it usually identifies the component and can turn a diagnostic visit into a parts-in-hand repair.
One symptom deserves singling out. If it cools weakly or ices up, the system is short of refrigerant, and a sealed system should never be short of refrigerant. Paying for a regas without finding and fixing the leak buys you a few months and then the same bill. It is also an offence to knowingly vent refrigerant.
On F-Gas: anything touching the refrigerant circuit legally requires an F-Gas registered engineer. We do not verify that for you — ask to see the registration and check it on the register itself.
Air conditioning repair cost by fault (2026)
| Fault | Typical 2026 cost | Notes |
|---|---|---|
| Call-out and diagnosis | £90–£150 | Often credited against the repair |
| Condensate drain blockage | £90–£180 | Water dripping from the indoor head |
| Sensor or thermistor | £120–£250 | Wrong temperature, short-cycling |
| Fan motor | £180–£400 | Noisy, rattling, or no airflow |
| Refrigerant leak repair and regas | £200–£450 | Cools weakly, ices up, runs constantly |
| Control PCB | £250–£450 | Dead or unresponsive to the remote |
| Compressor | £450–£900+ | Usually replace the unit on anything over ~8 years |
| Out-of-hours call-out | +£80–£160 | Evenings, weekends, peak season |
Figures match our AC repair cost guide. Refrigerant work is legally restricted to F-Gas registered engineers — check the register yourself.
AC repair calculator FAQs
Below about eight years, almost always. Beyond that, a failed compressor often costs more than half a new installed unit — and a new one will be markedly cheaper to run, so replacing is usually the better call.
A sealed system should never need topping up. Needing refrigerant means there is a leak, so a regas without finding and fixing that leak is money thrown away — and venting refrigerant is an offence.
Almost always a blocked condensate drain, one of the cheaper fixes at £90–£180. Left alone it will damage the wall and the unit.
You can clean filters and clear a drain. Anything touching the refrigerant circuit legally requires an F-Gas registered engineer.
Related cost guides
- AC repair guide — every fault priced
- Servicing costs — the annual visit that prevents most of them
- All AC costs — every system type side by side
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