clk 320 coolant loss

[darren23]

hi! i have 320 99 plate, with digital climate control, i am losing a small amount of coolant a week,when the engine is ticking over or low revs cold air comes out , once revving higher hot air comes out i normally have it set on 25c, if i leave it on hi it blows out normal, i also hear swishing of water behind middle vents. a few people have told me it could be, duo valve, recirculating pump or thermostat.. please help

 

[BlackC55]

I would say its more likely to be the duovalve.

 

[television]

Does look like the valve, have a look in the DIY section

 

[darren23]

thanks black & television i think i will go for that