MOT & Air Con: What You Need to Know

With the recent spell of good weather gracing the UK, the immediate instinct upon entering your car is to crank up the air conditioning. However, if you're met with nothing but hot air, you're likely in for a rather uncomfortable and sticky journey. At Five Star Autocentre, we understand the importance of staying cool and comfortable on the road. That's why we've put together this comprehensive guide to everything you need to know about your car's air conditioning system.

The Air Con Recharge Explained

While your car's air conditioning system is designed to be sealed, the demanding environment in which a vehicle operates can take its toll. The A/C system relies on a combination of rubber hoses and fixed aluminium pipes. Over time, these components can lead to a natural loss of refrigerant, often referred to as 'gas'. This refrigerant needs to be replenished periodically. Without the correct amount of refrigerant, your air conditioning system simply cannot effectively remove heat from the car's cabin. If the refrigerant level drops too low without your knowledge, the system will cease to function. This, coupled with prolonged periods of inactivity during the winter months, can unfortunately lead to component malfunction.

How a Healthy Air Con System Functions

When your air conditioning system is in good working order, it operates through a sophisticated cycle:

• Refrigerant Circulation: The journey begins with the compressor, which circulates the refrigerant. Initially in a liquid state, it transforms into a gas as it passes through the expansion valve.
• Heat Absorption: Cabin air then flows over the evaporator. During this process, the refrigerant absorbs heat from your car's interior. This heat absorption is entirely dependent on the presence of sufficient refrigerant.
• Compression and Heating: The refrigerant is then drawn back into the compressor, where its pressure and temperature significantly increase.
• Heat Dissipation: The now-pressurised gas is directed through the condenser. Your condenser fan blows ambient air over the condenser, effectively drawing heat out of the refrigerant and transferring it to the outside air. Your air conditioning system has now successfully moved the heat from the cabin to the exterior of the vehicle, leaving you with a refreshingly cool car interior.

MOT and Service Schedules: Is Air Con Included?

It's a common misconception that air conditioning checks are part of the standard MOT test. In reality, air conditioning is not included with your MOT. Furthermore, most vehicle manufacturers do not incorporate air conditioning checks into their routine service schedules. This means that if you want your air conditioning system inspected and maintained, you will need to book a dedicated air conditioning service. At Five Star Autocentre, we recommend an A/C system check annually, with a full air conditioning service advised every 24 months to ensure optimal performance and longevity.

Common Reasons for Air Con Failure

The most frequent culprit behind a malfunctioning air conditioning system is low refrigerant levels. When the quantity of refrigerant falls below the required threshold, the system loses its ability to efficiently extract heat and cool the cabin. As previously mentioned, refrigerant can be lost naturally through slow leaks or due to a specific fault within the system. However, this is not a cause for undue concern, as it's a relatively straightforward issue to rectify. We can replace the refrigerant and restore your air conditioning to full working order in no time.

Understanding a 'Re Gas'

If your car's refrigerant levels are low, it requires a 're gas'. This is a straightforward process that our expert technicians at Five Star Autocentre can expertly handle. Here's a breakdown of the steps involved in a typical air conditioning re gas:

What Constitutes an Air Con Service?

You might be wondering if there's a difference between an air con service and a simple re gas. The answer is a resounding yes. A comprehensive air con service goes beyond just replenishing the refrigerant; it ensures that all other critical components of the system are functioning correctly. This proactive maintenance is not only cost-effective in the long run but also vital for keeping your car's interior cool and free from unpleasant odours. Here are some of the key tasks typically included in an air conditioning service:

• Condenser Inspection: The A/C condenser is thoroughly inspected to ensure it's free from debris, which can impede efficient heat exchange.
• Compressor Drive Belt Check: The condition and tension of the compressor drive belt are checked for wear and tear.
• Pipework Inspection: Under-bonnet A/C pipes are visually inspected for security and any signs of damage or corrosion.
• Receiver Dryer/Accumulator Replacement: The refrigerant receiver dryer or accumulator, which removes moisture from the refrigerant, is often replaced as part of a service.
• Pollen Filter Check: The pollen filter (also known as the cabin filter) is inspected and replaced if necessary to prevent pollutants from entering the cabin and to ensure optimal airflow.
• Decontamination Treatment: An anti-bacterial or 'de-bug' treatment is applied to the system to eliminate bacteria and mould that can build up in the cabin vents, often causing musty smells.

We strongly advise having a full air con service every 24 months. This level of regular maintenance is a sound investment that can prevent costly system failures and keep your car's climate control running smoothly.

Maximising Your A/C System's Performance

One of the primary reasons why air conditioning systems can falter is simply due to lack of use. While it's tempting to only use your air conditioning during the sweltering summer months, this isn't ideal for the system's health. It's beneficial to operate your air conditioning periodically throughout the year, even during colder weather. This ensures that the compressor remains lubricated and all seals stay supple, preventing them from drying out and potentially developing leaks. Furthermore, utilising your air conditioning in winter offers significant advantages, such as rapidly demisting your windows by dehumidifying the cabin air, thereby improving visibility and road safety.

Troubleshooting Your Air Con

We've covered a great deal about how your car's air conditioning system works and why it might stop functioning. So, what should you do if you discover yours isn't performing as it should? The most effective course of action is to contact us at Five Star Autocentre. Our team possesses the expertise and experience to accurately diagnose the problem and carry out the necessary repairs swiftly. Don't endure a hot and uncomfortable journey; let us help you get back to enjoying a cool and pleasant driving experience.

Call Five Star Autocentre today on (01484) 54 54 22 to book your air conditioning service or re gas.

Frequently Asked Questions

Does a broken car air con affect my MOT?

No, a malfunctioning air conditioning system does not cause a vehicle to fail its MOT. The MOT test focuses on road safety and environmental emissions, and air conditioning is not a component assessed during this mandatory inspection.

Is air conditioning included in a car service?

Typically, air conditioning checks are not part of a standard car service as outlined by most manufacturers. It is usually an optional extra or a standalone service that needs to be booked separately.

How often should I get my air conditioning serviced?

It is generally recommended to have your car's air conditioning system serviced every 24 months. An annual check of the system's performance is also advisable, especially if you use it frequently.

Why is my car's air con blowing hot air?

The most common reason for this is a low level of refrigerant gas. This can be due to natural leakage over time or a fault within the system. Other causes can include a faulty compressor, a blocked condenser, or issues with the electrical system.

What is a 're gas' for my car's air conditioning?

A 're gas' is the process of replenishing the refrigerant gas in your car's air conditioning system. This involves removing the old refrigerant, checking for leaks, and then recharging the system with the correct amount of new refrigerant and lubricating oil.

Can I fix my car's air con myself?

While DIY air conditioning recharge kits are available, they are generally not recommended for the average car owner. The process requires specific knowledge and equipment to ensure it's done correctly and safely. Incorrect handling can lead to system damage or injury. It's best to leave this to qualified professionals.

What are the benefits of using air conditioning in winter?

Using your air conditioning in winter helps to dehumidify the air inside the car. This is extremely effective at clearing misted-up windows quickly, improving visibility and enhancing driving safety. It also helps to keep the air conditioning system lubricated and prevents seals from drying out.