Installing heater: Audi A3

🧭 Before you start

Fits: Audi A3 (8P, 2003–2012)

• Renewed: damaged seals

Don't miss

• Check all seals at the heater for damage prior to installation and replace damaged seals.Check attachment of the coolant pipes to the heat exchanger.

📋 Procedure

1. The assistance of a 2nd mechanic is required when installing the heater. [Note: Check all seals at the heater for damage prior to installation and replace damaged seals.Check attachment of the coolant pipes to the heat exchanger.]
2. Working from the passenger compartment, insert the moulded gasket (A) in the bulkhead (B), paying attention to the correct position of the moulded gasket (A) in the bulkhead.
3. Have a second person assist with heater installation.
4. Working from the engine compartment, have a second person guide the flange for the coolant pipes to the heat exchanger (A) through the lead-throughs of the grommet (B) on inserting the heater. [Note: On installing the heater, pay attention to both coolant pipes to the heat exchanger to ensure that they do not catch on the opening to the plenum chamber or on the noise insulation mat and become bent or damaged.Pay attention to the wiring harness. Pulling too firmly could damage individual wires.]
5. Re-install the components removed (with the exception of the driver's storage compartment) in the reverse order of removal . [Note: When installing the dash panel, make sure the intermediate "“defrost”" piece is properly positioned on the heater on insertion and that the defroster vent does not squash the intermediate piece on fitting.After installing the dash panel, check the exit direction and the distribution of the air flow from the defroster vent to the windscreen.]

6. Connect the coolant hoses to the heat exchanger correctly. Note the markings:
7. Check the installation position of the coolant hoses to the heat exchanger (they must not make contact with components which become warm) as well as the position and condition of the thermal insulation which may be attached to the coolant hoses (not fitted with all types of engine).
8. Bleed coolant circuit Engine, mechanics19.
9. Check the coolant circuit for leaks, paying particular attention to the connection between the coolant pipes and the heat exchanger and Engine, mechanics19.
10. Check that the grommet (B) is correctly positioned in the bulkhead.
11. If necessary, apply silicone adhesive sealant to the flanges for the coolant pipes to the heat exchanger (A) at the lead-throughs of the grommet (B) (to prevent the ingress of water).
12. Re-install the driver's storage compartment and the remaining components removed.
13. Check heater operation.
14. Check the air exit direction in line with the switch position (the gear mechanisms at the heater and heater controls cause the flexible shaft to rotate twice each time the switch is turned) .

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