Should you repair or replace your air conditioning?
It depends on the fault, the refrigerant, the age of the system and whether parts are still available. Most drain, sensor and board faults on a modern system are worth repairing. An R22 system with a refrigerant problem almost always needs replacing. Here's how to decide, and the UK rules behind it.
- diagnostic visit, deducted
- £125
- no R22 for servicing
- Since 2015
- new 2.5 kW system, inc. VAT
- From £1,850
- in writing, before any work
- Price first
Start with a proper diagnosis
A unit that won't cool might have a blocked filter, a failed sensor, a leak or a dead compressor, and the right answer is different for each. So start by finding out what's actually wrong.
Our diagnostic visit covers the first hour on site. The engineer finds the fault, checks the refrigerant type and the model, and gives you a written repair price. If replacing makes more sense, we'll say so and explain why. If you go ahead with the repair, the diagnostic fee comes off the bill.
The prices to compare
The diagnostic fee is deducted if you go ahead with the repair. New systems are fixed-price after a free survey.
- from£125inc. VAT
Repair diagnostic visit
First hour on site, deducted if you go ahead
- from£1,850inc. VAT
A bedroom or study
2.5 kW wall unit, 5 m pipe, fitted in a day
- from£2,050inc. VAT
A living room
3.5 kW wall unit
Check your refrigerant first
The refrigerant type is printed on the rating label of the outdoor unit. It has the biggest say in whether a repair is worth it.
| Refrigerant | What the rules say | What it means for you |
|---|---|---|
| R22 (HCFC-22) | Using it to maintain or service equipment was only allowed until 31 December 2014 | It can't be topped up. A leak or a refrigerant fault usually means replacing the system |
| R410A | GWP 2,088. New single splits under 3 kg using refrigerant with a GWP of 750 or more banned from 1 January 2025 | Existing systems can still be repaired and regassed. Worth repairing if the system is sound |
| R32 | GWP 675, below the 750 limit for new single splits | Current technology. Repair is usually the right answer |
Sources: Regulation (EC) No 1005/2009, article 11, and Regulation (EU) No 517/2014, Annex III, as they apply in Great Britain (legislation.gov.uk). GWP figures from Mitsubishi Electric UK's datasheets.
If your system runs on R22
R22 damages the ozone layer. Under the ozone regulation that still applies in Great Britain, recycled and reclaimed R22 could be used for servicing existing systems only until 31 December 2014. Since then, it can't be used to service or top up air conditioning at all.
An R22 system that still works can keep running. But any fault that means opening the refrigerant circuit, such as a leak or a compressor failure, can't be fixed by refilling with R22. At that point replacing the system is almost always the sensible answer. Electrical faults can sometimes still be repaired, but weigh that against a new system.
If your system runs on R410A
R410A isn't banned in existing systems. You can still have an R410A system serviced, repaired and regassed. The GB servicing ban on high-GWP refrigerants applies to gases with a GWP of 2,500 or more in larger refrigeration equipment, and R410A's GWP is 2,088.
What changed is new equipment. Since 1 January 2025, single split systems holding less than 3 kg of refrigerant with a GWP of 750 or more can't be placed on the GB market. So if a major part such as the outdoor unit fails, a matching new R410A system may be hard or impossible to buy, and the practical answer is usually a new R32 system with both indoor and outdoor units.
Common faults: repair or replace?
Our usual advice for home split systems. Every case is priced in writing after diagnosis.
| Fault | Usually | Why |
|---|---|---|
| Water dripping indoors | Repair | Normally a blocked drain or tray, often fixed in the diagnostic visit |
| Faulty sensor or thermistor | Repair | A low-cost part on most models |
| Fan motor | Repair | Worth it if the part is still available |
| Control board (PCB) | Repair, if the part is available | Boards can be expensive, so weigh the cost against a new system |
| Refrigerant leak, R32 or R410A | Repair | Find and fix the leak, then refill to the correct weight |
| Refrigerant leak, R22 | Replace | R22 can't be used to refill it |
| Compressor failure | Often replace | The most expensive part to replace, so the sums often favour a new system |
Lean towards replacing if
- It runs on R22
- The compressor or outdoor unit has failed on an older R410A system
- Parts for your model are no longer available, or the lead time is months
- The repair price is a large share of a new system, which starts from £1,850 for a 2.5 kW room
- It keeps breaking down, with different faults each year
- It was never the right size, so it's noisy, struggles in a heatwave or cycles on and off
- You want efficient heating through winter, and your model's efficiency is well below today's
Lean towards repairing if
- It runs on R32 or R410A and the fault is a drain, sensor, fan or board with parts available
- It's still under the manufacturer's warranty or our workmanship guarantee
- It's the right size and you're happy with how it performs
Efficiency and parts
Today's premium 2.5 kW units list a seasonal cooling efficiency (SEER) of about 9.5 to 10.5 and a heating SCOP of about 5.2, according to Daikin, Mitsubishi Electric and Panasonic. Find your own model's energy label or spec sheet to compare. If you only cool a few weeks a year, the saving rarely pays for a new system alone. If you heat with it all winter, it counts for more. Our running costs guide shows the sums.
Parts availability varies by brand and model, and manufacturers stop making parts for older ranges in time. At diagnosis we check whether the part is available and how long it will take, before you commit to anything.
Repair or replace questions
How long does air conditioning last?
It depends on how hard it works, where it's fitted and how well it's serviced. We don't judge on age alone. We look at the refrigerant, the condition of the outdoor unit and coils, and whether parts are still available.
Can R22 air conditioning still be regassed?
Not with R22. Using R22 to service or top up air conditioning has not been allowed since 31 December 2014. If an R22 system has lost refrigerant, replacing it is almost always the answer.
Is R410A being banned?
Not in existing systems. They can still be serviced, repaired and regassed. Since 1 January 2025, new single split systems under 3 kg using refrigerant with a GWP of 750 or more, which includes R410A, can't be placed on the GB market. New home systems use R32.
Can you replace just the outdoor unit?
Sometimes, if a compatible outdoor unit is still made for your indoor unit. For older R410A or R22 systems that's often not possible, so replacing both units is the usual answer. We check compatibility before quoting.
Will a replacement need planning permission?
Often not, for a heating-capable unit on a house in England that meets the permitted development rules. A replacement is treated like a new installation, so check our planning permission guide or ask us at the survey.