Heater Warm Air Flap Sticking - 2010 C3

[paul.h]

The warm air flap that controls the temperature in our 2010 C3 has started to stick a bit. This is causing the control cable from the rotary dial to bend and then not move the flap. A new cable did not help for long and as a temporary measure a rubber sleeve has been put on the cable to limit it bending. There is something wrong with the flap, possibly it is breaking up but to check it needs the heater removing. The dealer has said it needs a new heater unit at just over £1400 including the parts and about 8 hours labour and they had done a couple. Since the refrigerant needs removing/putting back it is not a complete DIY job.

 

Internet searches have not come up with anything or any repair kits like the C5 and C4 so may be it is early days for this to become a common problem but if buying a 2009 on C3 check the warm air rotary switch turns easily and fully.

[Rookie2]

I do know of an old trick for squealing heater blower fans, it may work on a sticking flap.

Simply set the fans away and spray high pressure WD40 (Aerosol) into the fresh air intake. It leaves a pong of wd40 in the car for a while bit it certainly gets it to the parts others cannot reach . A bit like Heinekin actually.

Quietens noisey motors, costs very little, no stripping down to do, you never  know, it may help

[paul.h]

The heater unit has now been replaced, £1352 at the dealer, and it now works normally. I kept the heater and whilst there is nothing obvious to see, the warm air flap is 2 separate flaps that move together linked by a plastic rod. When trying to move the flaps with the cam on the side of the heater, they are very stiff to  move and need more effort than can be achieved with the rotary switch cable which is quite flexible and just bends. Possibly grease in the right places may help but the unit is 2 plastic halves welded together so could get damaged whilst breaking it apart. I did start doing this just to have a look but the air con evaporator matrix and relief valve are built in to it and oil started to run out, so not wanting to mess up the kitchen floor gave up. Maybe a stonger cable such as used on bicycle brakes would help but a special fitting is needed to clip it to the heater control panel and the existing cable sleeve is too narrow to fit a new cable inside it.