The smell of moisture in the ventilation

[ing_Onopko]

Hello, guys,

I have a Citroen C4 1.6 HDi 84kw from 2012.
I was in an authorized service center a week ago to check the condition of the climate.
They checked everything, tested it with a vacuum, added a little compressor oil and freon and confirmed that the air conditioner is working.
What bothers me is the smell of moisture in the cabin when the air conditioner is not on, but only the ventilation. When the air conditioner is working, this smell is not felt.

Also, I noticed that when the air conditioner is working, water does not drip under the car as it should. What I was able to do was remove the side upholstery under the passenger's legs and check if the drain hose was broken, I poured water into it and the water was leaking so the hose was not broken.

Have any of you had similar experiences? How can I get rid of the smell of dampness in the cabin? Why isn't water leaking from under the car when the air conditioner is working and the drain hose is not plugged?

Thank you in advance!

[GiveMeABreak]

Make sure you have the system on AUTO and that recycled air is not activated.

Otherwise time to have the A/C system actually cleaned out and serviced and not just topped up. This involves vacuuming out all the refrigerant and oil, disinfecting the A/C system and then pressure testing, before refilling with the correct amount of oil and refrigerant.

If this doesn't resolve things, then you may have a blocked heater matrix.

[PaulC5]

The smell inside the cabin will be mould on the evaporator matrix. You can get aerosol cleaners to spray into the air inlet with the cabin filter removed, the blower on full to the central vents (not on recirc) and the air con on, then stop the blower and let it remove/kill the mould. You can also use a fine spray of Dettol non bleach surface cleanser to do the same thing at a tenth of the cost. If the drain pipe is not blocked, have you also made sure the connection upwards is not blocked ?

[NotAnInterestingName]

Check whether the scuttle panel drain holes at the bottom of the windscreen are blocked, they block fairly easily with a leaf or two and can cause rainwater to overflow into the ventilation air intake, especially if parked on a hill.

Change the pollen/cabin filter. It's such a pain of a job on many Citroens that it often gets left out of standard servicing, even if paid for. Many are lots of years old and full of all kinds of nastiness.

I've ruined a fan with a squirty can of sanitiser in a previous car. The fan was full of sticky residue, it went squeaky then stopped. I'll never use the stuff again.

[Rp0thejester]

I like the reply above, I found parking my car uphill, bonnet first would cause condensation to collect in the head lining as my car has a child mirror. It would then drip out when driving, but if not driven in a couple of weeks it stunk of mould. So to fix I parked facing downhill, job done

[ing_Onopko]

Dear All,

Thank you for all of your comments!
I hope it will be helpfull.