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Fuel Burning Heater

Overview

One of the best options a new owner could tick on a Range Rover is the Fuel Burning Heater. The Webasto ThermoTop C has been used in many applications, from Rovers to Renaults.

Unfortunately the option was rarely ticked on the petrol varient, but a few examples do exist. The fitment was standard on the TD6 however, although in most cases the FBH only provides Additional Heating as below. However with modification any TD6 FBH should be able to function as a park heater. More info here:

Parked Heating

When the ignition switch is in position I, parked heating can be selected on and off using the MID or MFD. When the ignition is off, parked heating can be set to come on at a programmed time or selected on and off using the remote handset. The programmed time is a start time for parked heating to begin within the next 24 hours and is entered into the instrument pack using the MID/MFD.

Once parked heating is on, if it is not selected off it will automatically time-out after 30 minutes. If the engine is started while parked heating is on:

  • If the engine coolant temperature is equal to or more than the heater coolant temperature, parked heating is switched off
  • If the engine coolant temperature is less than the heater coolant temperature, parked heating remains on until the engine coolant temperature reaches the heater coolant temperature.


Remotely Selected Parked Heating

When parked heating is selected on with the remote handset, the request is received by the FBH receiver via the TV antenna and TV receiver. The FBH receiver relays the request as a hardwired signal to the FBH ECU. On receipt of the request, the FBH ECU sends a FBH on request to the ATC ECU on the K bus. Provided there are no system faults, the ATC ECU then:

  • Returns a FBH on request to the FBH ECU, which starts FBH operation
  • Energises the changeover valve
  • Operates the blower at low speed
  • Opens the windscreen distribution flaps in the heater assembly and closes the face and footwell flaps
  • Transmits the FBH status on the K bus to the instrument pack

When the instrument pack receives the FBH status message, it outputs:

  • A FBH request to the MID/MFD on the I bus to operate the flashing LED on the MID/MFD panel
  • Ambient and engine temperatures to the ATC ECU and BCU on the K bus
  • A FBH request to the BCU on the K bus. If the ambient temperature is less than 5 °C (41 °F), the BCU activates the door mirror heaters for 3 minutes

Additional Heating

On Td6 models, additional heating reduces the heater warm-up time and is also used to maintain heater performance throughout the drive cycle. On V8 models, additional heating is only used to reduce the heater warm-up time at the beginning of the drive cycle, and only occurs if parked heating is already active when the engine starts.

The ATC ECU activates the additional heating mode when the engine is running and the following conditions coexist:

  • The ambient temperature is less than 5 °C (41 °F)
  • The engine coolant temperature is less than 75 °C (167 °F)
  • The heater coolant temperature is less than 75 °C (167 °F)
  • The reference temperature is 100%
  • The blower is on

Webasto Software

In theory one can communicate with the Webasto heater using the webasto software over the iBus, further information required here.


Webasto Software