Ultimate Guide: Car Air Con Regassing

Air con is an excellent function in many cars, mainly used during the hot weather to keep you cool and is a great tool to demist your windows during the winter.  

Keeping on top of your air conditioning servicing is essential as the system’s health will deteriorate over time, causing your car to run less efficiently. 

Read our guide to learn more about air con regassing and its importance. 

What is air con regassing?

An air conditioning regas involves removing the old refrigerant gas from the air-con system and replacing it with new refrigeration gas. 

How does air conditioning work?

A car air conditioning system works by moving the refrigerant through a high and low-pressure closed-loop system, which manipulates the refrigerant between a liquid and gaseous state. The refrigerant absorbs heat from the vehicle and delivers cool, dry air into your vehicle.  

Here is a more in-depth explanation of how a car air con works: 

  1. The refrigerant (gas) travels to the compressor. This is where the refrigerant will be compressed into high-pressure, high-temperature gas before travelling to the condenser.
  2. The condenser will disperse the heat out, and the high-pressure refrigerant gas drops in temperature and becomes a high-pressure liquid.  
  3. The high-pressure liquid passes through a receiver, removing any impurities before it reaches the thermal expansion valve.
  4. The high-pressure liquid expands and becomes a low-pressure liquid as it enters the low-pressure side of the loop system.
  5. The liquid is turned into a gas again as it passes through the evaporator, taking the heat from the vehicle.
  6. During this process, a fan blows over the exterior of the compressor, and cool air gets blown into the vehicle. 
  7. The low-pressure refrigeration gas enters the compressor again, and the process continues. 

How do I know if my air-con needs regassing?

It is important to be aware of the warning signs that your air con requires a regas; here are a few signs to look out for: 

Blowing out warm air

If your car is blowing out warm air, then this indicates that your air con could be low on refrigerant or that there could be a blockage such as a build-up of bacteria or a damaged ventilation fan.

Bad smell

A bad smell indicates that there is something wrong with your air con system. The smell could be due to a build-up of bacteria growing within your system, which over time could have a negative effect on your health.

Takes a long time to cool your car

Your air con may still be working; however, it is taking longer to cool your car than it used to; this could be a sign of inadequate refrigerant due to leakage or prolonged use. You shouldn’t wait until your air con completely stops giving you cold air; instead, you should have it serviced by a skilled technician, so you don’t cause any damage to the system by continuing to use it.

Unusual sounds

When you turn your air con on, you should hear the fan blowing cool air; any unusual sounds such as rattling and banging from your air con can be alarming as this indicates something could be wrong. This could be due to a broken fan belt, condenser, or debris blocking the fan. If this is the case, then it is essential for a technician to service your air con as soon as possible.

Can I regas my air con myself?

A skilled technician should perform air con regassing, although there are kits available for you to do it yourself. There are some positional risks and disadvantages such as: 

  • You could cause damage to your AC system, which could result in you having to get your air con repaired, which could be costly.  
  • Handling refrigerants can be unsafe, and you could freezer burn yourself if the gas comes into contact with your skin.
  • Mixing the old refrigerator with the new one could cause dangerous chemical reactions. 
  • They can be expensive – some of the kits can be either a similar price or more expensive than if you were to have a skilled technician perform them, making them not worthwhile.
  • It can be time-consuming, especially if you are unsure on how to perform the regas.  

By getting an accredited, trusted technician to perform your Car Regas Service you can have a worry-free experience without the risk or expensive cost.

What are the benefits of getting your air con regassed and serviced?

Fuel efficiency

Keeping your car up to date with regassing will save you fuel; if your air con is low in refrigerant, it will struggle to cool the air, causing the system to work harder and waste more fuel.

Summer weather

There would be nothing worse than on a hot summer day for your AC not to work, which is why keeping up to date with your servicing is essential for keeping you cool on hot days. 

Winter weather

Using your air con in winter has some great benefits; it is a great tool for demisting your car windows. In addition, the air coming out of the vents is dry, so the air con works as a dehumidifier. 

Another benefit is that turning your air-con on throughout the year will prevent it from seizing.


Regular air conditioning maintenance will prevent bacteria from building up over time. However, if not, this bacteria could be harmful to your health if exposed for an extended period.

How often does air con need regassing?

Over time, the refrigerant gas inside the air conditioning can leak out, causing the AC to struggle to cool the air. Many people wait until their car starts to blow out hot air; however, we recommend it is best to get your air conditioner serviced before that happens. The best option would be to get your air-con serviced every 2 years as a minimum to keep your car running efficiently. 

How long does it take for AC to work after regassing?

Depending on the vehicle, your AC should blow cold air soon after the regassing. Although, it shouldn’t take longer than 2 hours. If this is the case, this could be a sign of a problem, and a skilled technician should inspect your air con.

Is air-con part of my car MOT or service?

Air con regassing is not typically checked as part of your MOT or car service, although you can get your air con serviced at an additional cost. At Walker Cutting, we offer Car Air Conditioning Servicing, which includes cleaning, electrical calibration and regassing.

What are the differences between an air con recharge, regas and service?

Air conditioning recharge and regas

An air con recharge is just another name for air con regas, so this involves removing the old refrigerant gas from the air-con system and replacing it with new refrigeration gas.

Air conditioning service

An Air Con Service at Walker Cutting includes cleaning, electrical calibration and regassing.

Why does my air conditioning smell bad?

As your air con unit ages, it becomes weaker, making it harder to dispel bacteria. This can lead to a build-up of bacteria, giving you a bad odour when you turn your AC on. 

This is why keeping on top of your air conditioning maintenance is essential to keeping that bad odour away.

How can I look after my air conditioning system?

Here are some tips as to how you can make the most out of your air con:

  • You should use your air con throughout the year to stop it from seizing up, saving you money from getting it fixed. 
  • Servicing your AC every 2 years will keep it in good condition, rather than leaving it too late and a problem occurring, saving yourself money in the long run.  
  • When you have your AC on, make sure you close your windows; by having them open, you will waste fuel, and the cool air will be lost outside. 
  • Ensure you clear leaves and any debris that collects around the air intakes under the bonnet and below the windscreen. 

Need your air-con repaired, regassing or servicing?

Contact us for an appointment with one of our skilled Bosch accredited technicians at 01709 828220 or fill out this form, and one of our technicians will get back to you as soon as possible.

Comments for this post are closed.