Renault clio 1.2 dynamique 2004 heating

[McleodZz]

Hi, I have a Clio 1.2 2004 and the heating wont work.
It will come on cold but just wont get hot.
I have replaced the water filter and the fan belt, it has been flushed through and is clear and two mechanics have said the matrix is working correctly.
any ideas?
Thanks.

 

[Ads29]

Assuming it's not digital climate control, has the cable operating the heat mixture come off? Have a look in drivers footwell to the left of the pedals, should see 2 cables, 1 for heat mix and the other to set where the air comes out

 

[McleodZz]

Hi, sorry for late reply only just got chance to have a look, i did check that and both cables are connected ok by the looks of it.
someone has mentioned to me before about there might be a valve which could be stuck shut in one of the tubes going to/from the matrix which opens when it reaches a certain temperature, is that true and if so do you know where about it would be?
also the other thing apparently there could be a switch behind the heating control unit on the dash that could be stuck?
Thanks.