As UK temperatures soar, so does the cost of keeping cool. British drivers have to spend £102 million each year – an average bill of £426 – to fix faulty air-conditioning systems in their vehicles, according to new research by Warranty Direct.

Porsche owners are the most likely to feel the heat. The high-end German manufacturer’s product range is more prone to air-con failure than any other brand. SEAT and Chrysler are the second and third most likely vehicle makes to experience cooling problems.

The most common cause of the expected 238,000* air-con failures in the last 12 months is underuse or a simple malfunction; by using the air con only during the summer, or on hot days only, British drivers are leaving it prone to failure. When the system is inactive, the compressor isn’t lubricated properly and can fail.

The Warranty Direct study of three to seven year-old vehicles, which analysed 50,000 of its live policies, estimates the UK spends £102 million annually to keep its cars cool. While the average cost is £426, garage bills can soar to as high as £2,292 just to fix the air-con.

According to the data, the SEAT Alhambra (1996–present) is most likely to leave occupants hot under the collar with 7.5%, or one in thirteen models, expected to develop an air-con fault. The Porsche Boxster (2004–2012) and Volvo C70 (2006–present) also top the list of vehicles with unreliable air-conditioning systems.

Top 10 manufacturers for air-con failure

(Based on chance of failure in 3-7 year-old cars)

Make Largest air-con claim (£)
1 Porsche 1,325.32
2 Seat 435.32
3 Chrysler 1,013.10
4 Saab 1,476.80
5 Jaguar 988.05
6 Mercedes 2,968.52
7 Renault 921.60
8 Skoda 637.94
9 Ford 511.91
10 Vauxhall 1,641.93

Warranty Direct managing director, Duncan McClure Fisher, said: “An air-conditioning fault won’t typically leave you stranded on the hard shoulder but it can be one of the most expensive components to fix.

“Temperatures have already peaked above 28-degrees this year and it is usually the summertime when drivers realise their air-con has packed up. We highly recommend that drivers use the air-con from time-to-time, even if it is not particularly hot, to keep it in good order.”

Top 10 cars for air-con failure

(3-7 year-old cars)

Make Model Model year Chance of air-con failure (%)
1 Seat Alhambra (96 – ) 7.5
2 Porsche Boxster (04 – ) 5.3
3 Volvo C70 (06 – ) 4.7
4 Mercedes R-Class (06 – ) 4.3
5 Volkswagen Sharan (95 – ) 4.0
6 Nissan Note (06 – ) 3.9
7 Suzuki SX4 Saloon (09 – ) 3.6
8 Chrysler Grand Voyager (01 – 08) 3.6
9 Toyota Land Cruiser (03 – ) 3.4
10 Seat Altea (04 – ) 3.1

Warranty Direct cover starts from as little as £15 a month