Just to add that I have the same problem on my 4.4 --
On my third Full Fat RR

What's the best way to access the dual heater control valve and the auxillary pump?
Having looked with my endoscope camera there is no way to do it from below.
Will I have to remove the fuel filter assembly? Can't see any other way.
I've just put in a new burner canister in the FBH, to eradicate the smoke screen, but have a code saying the aux pump is grounded to earth.
Thanks Kev.

1 little bolt holds that pump in place just dive in undo it and pull the whole thing out plenty of hose there to allow you access it. Iv only done it on my m62 petrol not sure how much other stuff is in the way on the oil burner

Bit like my wife with the diesel. I can see it but can't touch it!!
Looks like the fuel filter housing has to come out.

Think I did mine with a couple of 1/4 inch extensions and a flexible knuckle

I’ve replaced the changeover valve on mine and it did nothing to help. However, I did opt for a cheapo part from the deepest, darkest recesses of the internet. My bad. I’m on the lookout for a decent OEM part without the unnecessarily exorbitant price of the LR genuine item. Does anyone know who the original manufacturer was? I’m guessing it may have been Gates? Can anyone confirm or correct? Part number LR016848. -------------------------
2012 4.4 TDV8 Vogue
2001 Audi A2 1.4 16V
2019 Skoda Kodiaq (don't ask...)

fmgL322 - search for BMW 7 series heater valves same part made by Gates


I managed to get a genuine BMW heater valve for £70 last year