Major breakdown on an air conditioner over 10 years old: repair or replace, and what about R410A?
L'équipe Proclimo
13 Oct 2026 - 08 min read
There are two ways to discover that your air conditioner has reached the end of its life. The first is brutal: one October morning, the unit trips into safety mode, the display shows an error code, and the compressor no longer starts. The second is insidious: for two or three seasons now, the unit has been cooling less effectively, you top it up with refrigerant every year, and nobody can really find the leak.
In both cases, the same question arises when the quote arrives: should you repair or replace? On equipment less than seven years old, the answer is almost always "repair". On a split or multi-split system more than ten years old running on R410A, the decision has become far tighter — because of the cost of parts, but also because of the European HFC phase-down schedule, which pushes the price of refrigerant up year after year.
Here is the method we apply in the field, part by part, with realistic price ranges for the Paris region.
The three faults that genuinely raise the question
Not every fault justifies a replacement. A remote control board, a temperature sensor, an indoor unit fan, a condensate pump: you repair them, full stop. Only three families of faults call the survival of the equipment into question.
1. The compressor
This is the heart of the machine and the most expensive part. A compressor for a domestic wall-mounted split represents, including labour and refrigerant, €900 to €2,000 depending on capacity and brand; on a multi-split or ducted system, you easily exceed €2,500. On top of that come the legally required refrigerant recovery, vacuum pull-down and full recharge.
A compressor almost never dies on its own. It usually fails because of a chronic refrigerant shortage (and therefore an untreated leak), a fouled outdoor coil, or electrical overheating. Replacing the compressor without addressing the root cause means signing up for a second breakdown within 24 months.
2. The inverter power board
On inverter machines, the power board controls the compressor speed. Replacing it costs €350 to €900 for parts and labour. The real risk isn't the price: it's availability. Manufacturers guarantee the supply of spare parts for a declared period — often 7 to 10 years after the model is withdrawn from sale, information you can demand from the seller under Article L. 111-4 of the French Consumer Code. Beyond that, you're looking at refurbished parts, or nothing at all.
3. The recurring refrigerant leak
This is the most common reason for our call-outs on older equipment. The unit loses its charge, blows lukewarm air, and frost appears on the connections. A clear leak on a flare fitting can be repaired for €250 to €450 including recharge. A leak on the heat exchanger (indoor or outdoor coil perforated by corrosion) is another story: a new coil often costs between €600 and €1,200 fitted, when it's still available in the catalogue.
Regulatory reminder: it is forbidden to knowingly recharge a leaking circuit. European Regulation (EU) 2024/573 and Articles R. 543-75 et seq. of the French Environmental Code require the leak to be repaired, followed by a verification leak test. A professional who offers you "just a gas top-up every spring" is breaking the law.
The R410A factor: why it changes the calculation in 2026
R410A is an HFC blend with a global warming potential (GWP) of around 2,088. It is used in almost all air conditioning systems installed in France between 2005 and 2018. It is not "banned" in the sense that your installation would have to be dismantled, but it is caught in a pincer movement between two mechanisms.
The European HFC quota. The 2024 F-Gas Regulation continues the progressive reduction of the quantities of HFCs placed on the European market, expressed in tonnes of CO₂ equivalent. The higher a refrigerant's GWP, the more quota it "consumes". The mechanical result: high-GWP refrigerants become scarce and their price rises in steps. R410A has already seen several price spikes since 2018.
The progressive ban on new equipment. New split and single-split systems placed on the market are switching to R32 (GWP ≈ 675) and, for smaller capacities, to R290 (propane). The deadlines in Regulation 2024/573 close the door on new high-GWP air conditioning equipment. You will no longer find a new R410A split, but refrigerant for servicing remains available, including in recycled or reclaimed quality — the regulations explicitly encourage this route.
In practical terms, for a homeowner in the Paris region in 2026:
| Situation | What it means |
|---|---|
| R410A unit with no leak, working properly | Nothing to do. Service it, keep an eye on it. No obligation to replace. |
| R410A unit with a located, repairable leak | Repair + recharge possible. Expect a higher refrigerant price than in 2018. |
| R410A unit with repeated leaks or charge lost several times | Replacement often becomes more rational than stubborn persistence. |
| R410A unit + dead compressor or heat exchanger | Replacement to be costed seriously against repair. |
If you want the detail on recharge prices and leak-tightness obligations, we have covered it separately in our article on air conditioning recharge and F-Gas regulations. No need to go over it again here.
The 50% rule: the costed decision
The rule we use is simple and fits in one sentence: if the repair exceeds 50% of the price of equivalent new equipment and the machine is more than ten years old, replace it.
A new 3.5 kW wall-mounted split, fitted, costs around €1,800 to €2,800 including VAT in the Paris region depending on brand, pipe run length and access constraints; a dual split rises to €3,000 to €4,500. Apply the calculation:
- Compressor at €1,400 on a 12-year-old machine whose replacement would cost €2,200 → replace.
- Power board at €420 on an 11-year-old machine otherwise in good condition → repair, that's 19% of the cost of new.
- Perforated outdoor coil at €900 on a 14-year-old machine → replace, especially if the refrigerant pipework can be reused.
Three adjustments to apply to this raw calculation:
- Efficiency. A 2012 split typically shows a SEER of around 5; a well-chosen 2026 model exceeds 7, sometimes 8.5. In real-world Paris-region use, that represents 20 to 35% less consumption for the same comfort. At current regulated electricity prices, a unit that runs a lot pays back part of the difference. Reading energy classes is explained in detail in our guide to the new energy label for reversible air conditioners.
- Heating. Many machines over ten years old are mediocre air conditioners in heating mode, or not reversible at all. A recent model heats properly down to -10 to -15 °C outdoors, which changes how the unit is used over six months of the year.
- VAT. With VAT dropping to 5.5% on high-performance reversible air-to-air heat pumps, the cost of a replacement has fallen compared with 2025, which shifts the 50% threshold in favour of buying new. Check the exact eligibility of the equipment proposed on your quote.
Before deciding: the five pieces of information to demand from your engineer
A repair quote on an old machine has no decision-making value if it doesn't answer these five points. Ask for them in writing.
- The exact nature of the fault and its cause. "Compressor dead" isn't enough. Why? Low charge, electrical fault, fouling? Without a cause, there's no guarantee the repair will hold.
- The availability of the part and its lead time. Original, compatible or refurbished part?
- The result of the leak test after the intervention, in the form of an explicit statement.
- The quantity of refrigerant to be recharged, in kg, and its unit price. This is the line that explodes on older machines.
- The warranty on the repair: parts and labour, for how long?
Also remember to locate the rating plate on the outdoor unit (refrigerant type, charge in kg, year) and, if you have it, the installation service logbook. A small heating and air conditioning service logbook kept near the electrical panel is worth more than three lost invoices: it lets you prove the history of interventions, which carries real weight in the event of a dispute or resale.
The special case of phantom leaks
The most expensive scenario is neither the compressor nor the board: it's the untraceable leak. It shows up as a slow loss, 10 to 20% of the charge per year, with no visible oil traces.
On an installation more than ten years old in a flat, the usual suspects are:
- flare fittings that are poorly tightened or worn out by thermal cycling;
- embedded refrigerant pipework without conduit, crushed or corroded inside a service duct;
- the indoor coil, perforated by "formicary" corrosion linked to the organic acids present in indoor air (cleaning products, solvents, varnishes);
- the service valves, whose caps have been left loose.
Detecting these leaks takes time: electronic detector, pressurised nitrogen, sometimes fluorescent dye. Budget €120 to €250 for leak detection, with no guarantee of success on the first visit. After two unsuccessful rounds on a twelve-year-old machine, persistence is no longer rational.
A common-sense measure in the meantime: monitor the temperatures actually achieved. An indoor thermometer-hygrometer placed in the main room, plus a measurement of the delta between return air and supply air, will tell you — without a refrigeration engineer — whether the machine is gradually losing performance. Write down the readings; it's an objective argument to put before the next diagnosis.
What replacement really involves
"Replacing" doesn't mean tearing everything out. On a wall-mounted split whose layout remains appropriate, three elements are often reusable:
- the outdoor unit bracket, if the fixing is sound;
- the wall penetration and the routing of the pipework;
- the dedicated electrical supply, if it meets standards and is correctly sized.
The refrigerant pipework, on the other hand, deserves serious discussion. Moving from R410A to R32 means either flushing or replacing it: compressor oils are compatible, but oil residues from the old circuit, especially after a compressor burnout, contaminate the new one. After a compressor failure, the pipework gets replaced. On a machine that is simply ageing but leak-tight, a manufacturer-approved pipework cleaning may be enough. R32 operating pressures are also slightly higher: the diameter and wall thickness of the copper must be checked.
For the stages and duration of a replacement job in a flat, we cover everything on the air conditioning installation page. In a block of flats, replacing a previously approved outdoor unit like for like is generally simpler than a first installation, but it doesn't exempt you from informing the managing agent — especially if the new model has different dimensions or noise levels.
Making the machine you keep last
If the decision leans towards repair, you might as well avoid reliving the same scene in two years' time. Three actions account for most of a split system's longevity:
- Clean the outdoor coil every year. Leaves, pollen, construction dust and poplar fluff block the fins and drive up discharge pressures — the leading cause of premature compressor death. A foam cleaner for air conditioning coils and a soft brush are enough for routine maintenance, outside the refrigerant circuit.
- Change the indoor filters according to actual usage, not once every three years. Compatible replacement air conditioner filters cost a few euros and prevent the coil from freezing.
- Have the leak-tightness checked by a technician holding the required certificate of competence, with a written report. It's the only way to detect a slow drift before it kills the compressor.
And before committing to anything on an older machine, a photo of the rating plate and a laser distance meter to record the room dimensions and the existing layout will save the technician an entire visit.
In summary
| Fault | Machine < 8 years | Machine 8-12 years | Machine > 12 years |
|---|---|---|---|
| Sensor, fan, condensate pump | Repair | Repair | Repair |
| Electronic board | Repair | Repair if part available | To be costed |
| Located, repairable leak | Repair | Repair | Repair once |
| Repeated leaks | Find the cause | Replace if 2nd failure | Replace |
| Compressor | Repair (warranty?) | To be costed (50% rule) | Replace |
| Perforated heat exchanger | Repair | To be costed | Replace |
The right decision is never "new is always better" or "keep repairing as long as it holds". It comes out of a written diagnosis, a verified parts price and a calculation over three to five years. Our technicians make the diagnosis, cost both scenarios side by side and let you decide — that's the principle behind our air conditioning repair service and our advisory support in the Paris region.
A breakdown right now, or doubts about a machine that loses its refrigerant every spring? Book an appointment: better a diagnosis in October than an emergency at the first heatwave.
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