Webasto Auxiliary Heater Installation Guide

Important Safety Information

WARNING: Improper installation or repair of Webasto heating systems can cause fires or the release of deadly carbon monoxide, leading to severe or fatal injuries.

Installation and repair require specialized training, technical documentation, special tools, and equipment. Only use genuine Webasto parts. Never attempt installation or repair without proper training and necessary documentation and tools.

Always follow all Webasto installation and repair instructions and heed all warnings. Initial startup must be performed with the Webasto Thermo Test diagnostics. Webasto is not liable for defects or damages caused by installation performed by untrained personnel.

Scope of Document

This installation documentation applies to Skoda Octavia vehicles (1.6 and 2.0 TDI Common Rail) from model year 2009 onwards, provided no technical changes to the vehicle affect the installation. Deviations from this documentation may be necessary depending on the vehicle's version and equipment. Always adhere to the instructions in this document, the operating manual, and the installation manual for the Thermo Top C/E, as well as the vehicle manufacturer's specifications.

General Notes

Installation should follow standard technical practices. Hoses, lines, and wiring harnesses should be secured with cable ties to existing vehicle lines and harnesses unless otherwise specified. Sharp edges must be protected with hose protection (cut fuel hose). Bare metal surfaces, such as drill holes, should be treated with corrosion protection wax.

Special Tools

• Torque wrench for 2.0 - 10 Nm
• Hose clamps

Table of Contents Overview

The document is structured with markings on the outer edge of each page for quick reference to different sections: Mechanics, Electrical, Coolant Circuit, Fuel, Exhaust, and Combustion Air.

Symbols Used

• Warning Triangle: Danger of injury or fatal accidents.
• Exclamation Mark in Triangle: Danger of component damage.
• Fire Symbol: Danger of fire and explosion.
• Information Symbol (i): Reference to general installation instructions for Webasto components or vehicle-specific manufacturer documentation.
• Lightbulb Symbol: Technical peculiarity.
• Arrow in Vehicle Pictogram: Indicates position on the vehicle and viewing direction.

Preparation (Vorarbeiten)

Before starting installation, perform the following steps:

• Open and ventilate the fuel tank.
• Transfer the factory number from the original nameplate to the duplicate nameplate.
• Remove the incorrect year from the duplicate nameplate and affix it visibly.
• Disconnect the battery.
• Remove the battery and battery carrier.
• Remove the engine cover.
• Loosen the water box cover.
• Remove the front left wheel.
• Remove the front section of the front left wheel arch liner.
• Remove the left fog light or the cover if the vehicle has no fog lights.
• Remove the underbody protection.
• Remove the right underbody paneling.
• Remove the rear seat bench.
• Open the service flap on the fuel pump assembly on the right.
• Remove the driver-side footwell trim.
• Remove the lower dashboard trim on the driver's side.
• For vehicles with Climatronic: Remove the passenger-side footwell trim.

Attach page 34, "Operating Instructions for the End Customer," to the installation manual.

Heater / Installation Kit

Required components:

• 1x Scope of delivery Thermo Top E / C / P
• 1x Installation Kit Skoda 1.6 and 2.0 TDI Common Rail SG
• 1x Control unit

Additionally required for Climatronic:

• 1x Kit IPCU for Climatronic

Recommended Heater for Vehicle Class:

• Small Cars: Thermo Top E
• Mid-size, Estate: Thermo Top C

The choice of heater depends on the vehicle's interior space and the customer's comfort requirements.

Electrical Connections (Elektrik)

Wiring Harness Routing: Route the heater wiring harness through the cable duct under the battery and secure with cable ties.

Engine Compartment Cable Routing: Use the vehicle's own cable routing points. Route wiring harnesses for blower control and control unit.

Fuel Pump Wiring Harness: Route the fuel pump wiring harness and cable harness along the vehicle's fuel lines under the vehicle.

Interior Cable Routing: Use the vehicle's own cable routing points. Route wiring harnesses for blower control and control unit.

Fuse Holder and K3 Relay

Boreholes for screws: Boreholes 3 are prepared from the rear for countersunk screws M5.

• 1. Cover of fuse/relay carrier in engine compartment.
• 2. Cut away the web in the hatched area.
• 3. Borehole Ø 5 [2x].

Mounting: Use countersunk screw M5x12 [2x].

For vehicles with Climatronic: Replace fuse F3 25A with the supplied 3A fuse.

• 1. Nut M5
• 2. Body washer (between cover and mounting plate)
• 3. Mounting plate
• 4. Nut M5
• 5. Relay K3
• 6. Fuse holder

Ground Connection: Route and connect the ground wire (brown) to the vehicle's own ground point below the headlight.

• 1. Fuse/relay carrier
• 2. Vehicle's own main fuse
• 3. Positive line (red)

Blower Control Climatic

The diagram shows the electrical connections for the Climatic system. Key components include the Webasto heater (HG), fuse F3, relay K3, and diagnostic connector (Dg). Vehicle components include SC40 (blower fuse), J301 (climate control unit), N24 (resistor group), and V2 (blower motor).

Wire colors and symbols legend is provided.

Connection: Connect to the vehicle's own fuse holder (dashboard top left). Disconnect wire sw/bl 42 from fuse output SC40. Establish connection according to the wiring diagram.

• 1. Wire red K3/87a inserted into fuse output SC40.
• 2. AMP connector housing.
• 3. Wire black K3/30.

Blower Control Climatronic

The diagram illustrates the electrical connections for the Climatronic system. Webasto components include HG, X1 (6-pin connector), F3 (fuse), K3 (relay), and IPCU (pulse width modulator). Vehicle components include SC22 (blower fuse), J255 (Climatronic control unit), V2 (blower motor), and J126 (blower control unit).

Wire colors and symbols legend is provided.

Note: Fuse F3 25A must be replaced with 5A for Climatronic.

IPCU Preparation

Connections: Establish connections as per the wiring diagram. Insulate and secure wire red 2 from K3/87a.

• 1. Wire black K3/30.
• 3. IPCU module socket.
• 4. Wire green/white IPCU/86.
• 5. AMP connector.

IPCU Module Placement: The location of the free connector slot depends on the vehicle's equipment.

• 1. Wire brown IPCU/85.
• 2. IPCU module socket installed.
• 3. IPCU wiring harness.

Ground Connection: Use the vehicle's own screw. Route wire brown IPCU/85.

Wiring Harness Routing: Route the wiring harness from the IPCU module to the air duct towards the center console. Install the IPCU.

Blower Unit Connection

Route the wiring harness from the IPCU module to the vehicle's own lines for the blower unit.

Disconnect Blower Unit: Disconnect the blower unit. Establish connections as per the wiring diagram.

• 1. IPCU wiring harness.
• 2. Blower unit.

Reconnect Blower Unit: Reinstall the blower unit. Install the IPCU wiring harness.

Control Unit Installation

Pre-selector Timer (Vorwahluhr):

• 1. Summer/Winter switch.
• 2. Pre-selector timer.

Optional Telestart: Secure the receiver with adhesive tape.

• 1. Antenna.

Temperature Sensor HTM100: Secure the temperature sensor with adhesive tape.

Heater Pre-assembly (Heizgerät vormontieren)

Combustion Air Line: Cut combustion air line to a length of 250 mm (Section X to be discarded).

Mounting Heater: Insert a washer between the heater and the bracket at positions 2.

• 1. Distance nut M6x30.
• 2. Ejot screw, washer [2x].
• 3. Hose clamp Ø 27.
• 4. Combustion air line.
• 5. Bracket.

Assembly:

• 1. Strut.
• 2. Ejot screw [2x].
• 3. Silencer.
• 4. Retaining clip in bore hole.
• 5. Combustion air line.
• 6. Hose piece, hose clamp Ø 10 [2x].
• 7. Fuel line.

Exhaust System Preparation (Abgas vorbereiten)

Exhaust Pipe: Cut exhaust pipe to 190 mm (a) and exhaust end piece to 240 mm (b) (Section X to be discarded).

• 1. Screw M6x16, spring washer.
• 2. Hose clamp [2x].
• 3. Profile rubber red, without groove.
• 4. Exhaust pipe with insulation.
• 5. Silencer.

Exhaust System Assembly:

• 1. Hose clamp.
• 2. Profile rubber red, without groove.
• 3. Exhaust end piece.

Coolant Circuit Preparation (Kühlmittelkreislauf vorbereiten)

1.6 TDI: Cut off section X. Dimensions: B = 840 mm, C = 100 mm, D = 720 mm.

Slide protective fabric hoses onto hoses A and C and cut to length. Cut heat shrink tubing.

• 1. Heat shrink tubing, length 25 [4x].

Water Hose Preparation:

• 1. Hose clamp Ø 27.
• 2. Cable ties [2x].
• 3. Hose clamp Ø 27.
• 4. Connecting pipe 20x20.

Hose C Assembly:

• 1. Connecting pipe 20x20, hose clamp Ø 27 [2x].
• 2. Connecting pipe 18x20, hose clamp Ø 27.

Hose A and B Preparation:

• 1. Hose clamp Ø 27.
• 2. Hose clamp Ø 27.

Disconnecting Hose: Disconnect hose from heat exchanger inlet 3. Reuse hose clamp 2. Remove heat exchanger inlet coupling 3.

• 1. Vehicle-specific coupling for heat exchanger.
• 2. Black rubber profile.
• 3. Hose clamp Ø 25.
• 4. Connecting pipe 18x20.

Align vehicle-specific hose clamps 1 [3x] as shown.

Heater Installation (Heizgerät montieren)

Prepare Installation Location: Secure body washers with kit or similar to prevent falling.

• 1. Body washer on vehicle-specific stud [3x].
• 2. Edge protection 100.

Mount Heater: Use body washer and nut M8 [3x].

Align Exhaust System: Ensure clearance of the exhaust system with vehicle components and lines.

• 1. Vehicle-specific wiring harnesses (secured with cable ties).
• 2. Horn.
• 3. Exhaust pipe.

Align Exhaust System: Ensure clearance of the exhaust system with vehicle components and lines.

• 1. Exhaust pipe.
• 2. Vehicle-specific wiring harnesses (secured with cable ties).
• 3. Horn.

Cable Harness Attachment

Pierce the perforation of the heater cover at position 2. Insert clip cable tie and secure the heater wiring harness 1.

Combustion air silencer tied back for demonstration purposes.

• 1. Cable tie.
• 2. Heater wiring harness.
• 3. Edge protection 50.

Fuel System (Brennstoff)

CAUTION: Open fuel filler cap, ventilate tank, and close again. Collect any spilled fuel in a suitable container.

Route the fuel line and the dosing pump wiring harness so they are protected against stone impact. Secure with cable ties unless otherwise specified. Protect fuel lines and wiring harnesses on sharp edges with hose protection.

Routing: Route the fuel line and the dosing pump wiring harness according to the wiring harness routing diagram.

Fuel Line and Dosing Pump Wiring Harness Routing: Route the fuel line and dosing pump wiring harness to the right in the water box and secure to vehicle-specific lines with cable ties. Ensure clearance for the wiper linkage. Route the fuel line and dosing pump wiring harness in the conduit to the underbody.

Route the fuel line and dosing pump wiring harness along the vehicle's fuel lines to the tank.

• 1. Conduit.
• 2. Existing feed-through [2x].

Bracket Relocation

Remove plug 3 for mounting. Remove the handbrake cable bracket at position 2 and mount it at position 1.

Dosing Pump Mounting

Reinstall plug 4 after mounting the plug.

• 1. Dosing pump wiring harness, connector installed.
• 2. Rubberized pipe clamp, nut, vibration damper.
• 3. Dosing pump.
• 5. Fuel line, hose piece, hose clamp Ø 10 [2x].

Steigrohr and Formschlauch Cutting

Cut 3 mm from the blind plug 1.

Tank Connection

Ensure sufficient clearance to adjacent components, especially the fuel level sensor.

• 1. Hose clamp Ø 13.5.
• 2. Fuel line.
• 3. Hose clamp Ø 10.
• 4. Formed hose with Steigrohr.

Dosing Pump Connection

• 1. Hose piece, hose clamp Ø 10 [2x].
• 2. Fuel line.

Coolant Circuit 1.6 TDI

CAUTION: Collect any leaking coolant in a suitable container! Route hoses without kinks! Secure with cable ties as described. Position clamps so no other hose can be damaged. Fill the heater with coolant during hose installation.

The connection is made "inline" according to the following diagram.

Legend for hoses and clamps:

• Unspecified hose clamps: Ø 27
• Unspecified connecting pipes: Ø 20x20
• All hose clamps: Ø 20-27
• 1 = Black rubber profile
• 2 = Hose clamp
• Ø 25 = Hose clamp
• 3 = Connecting pipes
• D = 18x20 connecting pipe

Hose Alignment

Align vehicle-specific hose clamps 1 [2x] as shown (turn counter-clockwise).

Clip Cable Tie Mounting

Drill Ø 6 mm hole at position 1. Be careful of underlying lines when drilling. Insert clip cable tie 1.

• 2. Edge protection 50.

Insert clip cable ties 1 [2x] into the holes of the water hose bracket 2.

• 3. Screw M6x20, nut, existing borehole.

Close clip cable ties 1 [3x]!

Bracket Mounting

Mount bracket.

Engine Compartment Routing

Route hose to engine output.

Heat Exchanger Inlet Connection

Secure hose B and D with cable ties 1.

Position black rubber profile.

Hose Alignment

Align hoses.

Coolant Circuit 2.0 TDI

CAUTION: Collect any leaking coolant in a suitable container! Route hoses without kinks! Secure with cable ties as described. Position clamps so no other hose can be damaged. Fill the heater with coolant during hose installation.

The connection is made "inline" according to the following diagram.

Legend for hoses and clamps:

• All hose clamps: Ø 27
• 1 = Vehicle-specific hose clamp
• Connecting pipes: Ø 20x20
• All hose clamps: Ø 20-27

Hose Alignment

Align vehicle-specific hose clamps 1 [2x] as shown (turn counter-clockwise).

Clip Cable Tie Mounting

Drill Ø 6 mm hole at position 1. Be careful of underlying lines when drilling. Insert clip cable tie 1.

• 2. Edge protection 50.

Insert clip cable ties 1 [2x] into the holes of the water hose bracket 2.

• 3. Screw M6x20, nut, existing borehole.

Close clip cable ties 1 [3x]!

Bracket Mounting

Mount bracket.

Engine Compartment Routing

Route hose to engine output.

Heat Exchanger Inlet Connection

Secure hose A and C with cable ties.

Ensure sufficient clearance to adjacent components.

Hose Alignment

Align hoses.

Air Filter Housing Preparation

For all vehicles: The position of the drain pipe may vary. Glue the protective cover 2 [2x] to the air filter housing 1 as shown.

Variant 1: If drain pipe 1 is present as shown, route it parallel to water hose C/D.

If drain pipe 2 is present as shown, secure it to the strut with cable tie 1.

Variant 2: If drain pipe 1 is present as shown, route it between water hoses A/B and C/D.

Exhaust System

Align exhaust end piece 2 and profile rubber 1 as shown. Ensure sufficient clearance between the exhaust end piece and the wheel arch liner.

Remove insulation, if present, at position 2.

• 1. Underbody protection.
• 2. Borehole Ø 42.

Align exhaust end piece 3 flush with profile rubber 2.

• 1. Underbody protection.

Final Work (Abschließende Arbeiten)

CAUTION: Reinstall removed parts in reverse order. Check all hose connections, clamps, and electrical connections for secure fit. Insulate and secure all loose lines. Use only coolant approved by the vehicle manufacturer. Treat heater components with corrosion protection wax (Tectyl 100K, Order No. 111329).

• Connect battery.
• Fill and vent the coolant circuit according to the vehicle manufacturer's instructions.
• Set pre-selector timer, pair Telestart transmitter.
• Configure climate control unit according to "Operating Instructions for the End Customer."
• Attach the "Switch off auxiliary heater before refueling" notice near the filler neck.
• Initial startup and function test: refer to installation instructions.

Operating Instructions for the End Customer (Bedienungshinweise für den Endkunden)

Please refer to and attach the vehicle's operating manual.

Note: We recommend matching the heating time to the driving time. Heating time = Driving time. Example: For a driving time of approx. 20 minutes (one way), we recommend a heating duration of no more than 20 minutes.

If the optional Summer/Winter switch is installed, set it according to the season. The heater will heat in the Winter position and activate only the vehicle fan for ventilation in the Summer position.

For vehicles with interior monitoring, this must be deactivated in addition to the vehicle settings for the heating process. Refer to the vehicle's operating manual for deactivation instructions.

Before parking the vehicle, set the following:

Climatic:

• 1. Air outlet to windshield.
• 2. Fan speed to level "1" or possibly "2".
• 3. Temperature to "max."

Climatronic:

• 1. Air outlet to windshield.
• 2. Temperature to "HI" on both sides.