RiverBlanche wrote:

JMC wrote:

The FBH warms the cabin, not the engine!!

other way around

the FBH, as already said, is to help get the engine up to temp quicker, a by product is it can be used to warm the inside of the car as well as it is heating the coolant system.

Hi,

dont dispute it Can be used to heat the cabin but I stand by what I have wrote,
still think my understanding is correct that L/R fit a FBH to help the engine get to temp, as the FBH heats the water in the coolant circuit,
not sure which they fitted it to first think a FL1 but the first time I came across a FBH was in a D3 and RRS1 these did not heat inside the car at all (until you started the engine anyway) I wired a remote start to the RRS1 to warm the engine before staring.
in the D4 and RRS2 we had timed climate and a remote fob and these did heat inside the cabin, as the FBH runs it heats the coolant circuit which I understood for the L320 works the same heating the coolant in the engine (thermostat shut) and the cabin heating circuit to preheat the cabin and warm the engine before starting the engine.

agree it fires on its own within certain parameters below 5 degrees, more than 1/4 tank fuel and this is to help get the engine get up to and keep at temp quickly and thats the main reason L/R fit a FBH to warm the engine and a by-product is you can warm the cabin as well.