Remove the heater (see Removal the heater).
Using a Phillips screwdriver, unscrew the two screws
and we separate the distribution damper housing and the fan housing.
We remove the gasket.
Using a Phillips screwdriver, unscrew eleven screws
and separate the distribution valve housing into two parts.
We remove the heater radiator from the housing.
We install the heater radiator in the reverse order.
To replace the damper
use a screwdriver to press the sector lock (for clarity, shown on the removed sector)… …and remove the damper drive sector.
We replace the faulty valve.
We install the damper drive sector so that the double tooth of the sector coincides with the wide recess on the damper drive lever.
We assemble the heater in the reverse order.