3233115 - L55 HEATER NOT HEATING

The fan works properly and sends air into the interior compartment in accordance with the set flows, but this air does not ensure the required heating.
Results of the tests
1HEATER PIPE CHECKAll OKProblems metOperation
Check the efficiency and the seal of the supply and return pipes from the heater; with the engine hot, the pipes should be hot Continue to Step 2 Pipes not connectedRestore the correct connection
Pipes dirty or obstructed Clean the pipes or replace them Op. 5010A10
2CHECKING MIXER CONTROL CABLEAll OKProblems metOperation
Check the mixer control cable is correctly fitted. Continue to Step 3 Connection defective Adjust correction or change the cable Op.   5020B42 
3HEATER RADIATOR CHECKAll OKProblems metOperation
Check the seal of the heater radiator Continue to Step 4 Pipes not connectedRestore the correct connection
Radiator dirty or obstructed Clean the radiator or replace it Op.   5020A30 
4CHECK CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsSearch for the fault starting from another symptom'