Air conditioning loses a little refrigerant every year by design. Most systems that blow warm are not broken — they are simply low, and a recharge restores them. Some are genuinely leaking, and topping those up repeatedly just vents refrigerant into the atmosphere.
We test the pressures first to find out which situation you are in, then recharge or repair accordingly.
Refrigerant is not consumed the way fuel is. A system that is low has lost it somewhere, and on a system that has never been touched that loss is usually slow permeation through the flexible hoses and shaft seals — normal, gradual, and correctly fixed by recharging. A system that ran out a year after its last recharge is leaking properly, and topping that one up repeatedly means paying for refrigerant every summer while venting it into the atmosphere in between. Dye and an electronic sniffer find the leak; the pressure readings tell us which of the two situations we are in before anything is connected.
The refrigerant also carries the compressor's oil around the system, which is why running an air conditioning system that is low is worse than not running it at all — the compressor is the most expensive component in the loop and it is the one starved first. The other habit worth having is running the air conditioning for a few minutes every couple of weeks through the winter. It keeps the shaft seal lubricated and pliable, and a seal that has spent six months dry is a common reason a system that worked fine in September blows warm in May.
What the service covers
- System pressure test
- Refrigerant recharge
- Leak detection and repair
- Condenser and compressor diagnosis
Signs you need air conditioning
- The air is cool rather than cold, or cools only while the car is moving
- It blows warm on one side and cold on the other
- A rattle or squeal from the engine bay when the air conditioning is switched on
- A musty smell from the vents when the fan first starts
- The system stopped working entirely over the winter
- Windows that take far longer to demist than they used to
What affects the cost
Every job is quoted before we start. These are the things that move the number — call the shop and describe the car and we will give you the figure for yours.
- Whether the fix is a recharge or a leak repair — and where the leak is, since a hose is a different job from an evaporator buried in the dash
- Which refrigerant the system uses: R-1234yf, fitted to most newer vehicles, costs substantially more than the older R-134a
- How much refrigerant the system holds
- Whether the compressor, condenser or expansion valve has failed rather than simply run low
- Whether the cabin filter is due at the same time, which is cheap and usually is
Air Conditioning questions
Why is my car's air conditioning blowing warm?
Most often the system is simply low on refrigerant, which every system loses slowly by permeation through hoses and seals. It can also be an electrical fault stopping the compressor engaging, a blocked condenser, or a failed expansion valve. A pressure test separates those quickly, which is why it comes before anything is connected or replaced.
How often does air conditioning need recharging?
There is no fixed interval, because it depends on how fast a given system permeates. Many go five years or more between recharges. What matters is the pattern: a system that needs topping up again within a year is leaking, and repeated recharging just vents refrigerant while postponing the repair.
Is it bad to run the air conditioning when it is low?
Yes. The refrigerant carries the compressor's lubricating oil around the system, so a low charge means the compressor — the most expensive part in the loop — runs short of oil. If the air is not getting cold, it is worth switching the system off until it has been tested.
Should I use the air conditioning in winter?
Worth doing, for two reasons. Running it for a few minutes every couple of weeks keeps the compressor shaft seal lubricated, which is a common cause of systems that worked in autumn and blow warm in spring. It also dehumidifies the air, so it clears a misted windscreen considerably faster than heat alone.
Why does my air conditioning smell musty?
Usually mould and bacteria on the evaporator, which sits wet and dark behind the dash, combined with a cabin filter that is overdue. A new filter and treating the evaporator normally deals with it. Running the fan without the compressor for the last minute or two of a journey helps the evaporator dry out and keeps it from coming back.