W222 Air Conditioning not coming on

[HorseAndJockey]

Hi, My 2014 seems to have developed a problem with the Air Conditioning.

On the digital display the checkbox for the aircon isn't ticked. And when I try to tick it it unticks straight away and doesn't cool the car down. Anything easy to check?

TIA

 

[mioba]

Welcome to the forum and do stick around.

When was it last regassed. I regas would be the first port of call. Gas last about 6-8 years.

 

[HorseAndJockey]

Not sure tbh. Its always been maintained at Mercedes Dealers. Would they re gas as part of the servicing normally?

 

[Blobcat]

Not sure tbh. Its always been maintained at Mercedes Dealers. Would they re gas as part of the servicing normally?

No

 

[Ron240]

Its always been maintained at Mercedes Dealers. Would they re gas as part of the servicing normally?

Something like this would always be additional and charged on top of routine servicing.

 

[HorseAndJockey]

Something like this would always be additional and charged on top of routine servicing.

Thanks Ron

 

[mioba]

With some models the system needs to be reset after a regas. So suggest you find a indy with regas facilities and star.

Also as mentioned - AC Refill is not a service item.

 

[HorseAndJockey]

All sorted now. The gas was very slightly low so the sensor wouldn't let it turn on. They re-gassed and added a dye and its now working great. They were really good - Halfords Hemel Hempstead garage (not at the store)

 

[mioba]

Glad you are sorted.
If it stops cooling after a few days you have a leak. But I doubt it.
Indeed the sensors switch the pump off as the AC gas contains a lube, no gas, no lube, motors dead, so its a protection feature.
Nearly all the gases now contain UV dye to make finding leaks much easier. This wasn't the case 15 years ago.
6 years time, get it topped again.

 

[HorseAndJockey]

Glad you are sorted.
If it stops cooling after a few days you have a leak. But I doubt it.
Indeed the sensors switch the pump off as the AC gas contains a lube, no gas, no lube, motors dead, so its a protection feature.
Nearly all the gases now contain UV dye to make finding leaks much easier. This wasn't the case 15 years ago.
6 years time, get it topped again.

@mioba Thanks

 

[alexanderfoti]

No

It is on certain gas types (R744 etc). The W222 has this so it may be included.

 

[mattkh]

All sorted now. The gas was very slightly low so the sensor wouldn't let it turn on. They re-gassed and added a dye and its now working great. They were really good - Halfords Hemel Hempstead garage (not at the store)

Well done Halfords garage.
My understanding is that the gas has to be very low for the sensor to disallow.

 

[alexanderfoti]

Well done Halfords garage.
My understanding is that the gas has to be very low for the sensor to disallow.

It's done on pressure.

On a system with 800G in it, the pressure when static remains the same regardless of amount of gas, until it gets to 100g or so, then starts to drop.