Your cars air conditioning system will lose 10-15% of its refrigerant every year, which can cause a build up of fungus and bacteria within the evaporator core, this can emit a peculiar smell and sometimes lead to an allergic reaction in extreme cases.

Your owners manual will recommend that you have your Air Con looked at once every 18 months, although this doesn't fall under the remit of a standard service on most modern vehicles. It is an extra that if you remember to ask to get done can cost you an arm and a leg in a main dealer.

The state of your Air Con is vital to having an enjoyable drive and as such you should watch out for the following symptoms that your Air Con is faulty.