Shutdown

Shutdown
The FBH system is de-activated when the alternator power supply to the FBH unit is disconnected, either by the engine stopping or, if the ambient temperature increases to 5 degrees C (41 degrees F) or above, by the contacts in the air temperature sensor opening. If the system is active when the alternator power supply is disconnected, the ECU de-energises the FBH fuel pump to stop combustion, but continues operation of the combustion air fan and the circulation pump to cool down the FBH unit. The cool down time depends on the combustion load at the time the alternator power input is disconnected.

Cool down times

Combustion load Cool down time,seconds
Part 100
Full 175